Hvis det er indvoldsorm, så opdager man det ved at aflevere en afføringsprøve til sin læge. Derefter undersøges prøven for parasitæg. Finder man f.eks. de her flotte piskeormsæg eller spoleormsæg, kan man stille diagnosen. Hvis man har børneorm kan diagnosen stilles ved at lave en såkaldt tape-prøve eller med en DNA analyse.

Nej, det kan de ikke. De er stendøde, men stadig meget flotte at kigge på.

Det er et godt spørgsmål. Det skyldes at vi har fået indført toiletter og har god hygiejne. De her infektioner smitter med afføring, og så længe vi ikke får afføringen ud i urtehaven eller miljøet omkring os, sker der ikke smitte, og så stopper ormens livscyklus. Det skyldes at æggene skal ligge og modne i miljøet først før de er smittedygtige. Det er i modsætning til børneorm æg som meget hurtigt bliver smittedygtige og det er grunden til at vi stadig har børneorm i Danmark selv om at vi bruger toilet.

Godt spørgsmål - vi ved dog ikke helt svaret på det. Der var tidligere nogle dyr som vi troede ikke havde mikrober, men som vi fandt ud af har. Det er dog meget svært at forklare hvad disse mikrober gør. Men som vi ser på det nu, tror vi at næsten alle dyr har mikrober.

Nej desværre. Det skyldes sammenhængen mellem genom og mikrobiom. Det er ligesom pandaen, som ikke kan ændre dens mikrobiom da den mangler et bestemt gen til at kunne fordøje planter med plantebakterier. Vi har samme problem, da vi heller ikke har et gen i vores genom, som er nødvendigt for nedbrydning af plantemateriale som græs.

Der findes mikrober som kan fordøje plast. Hvis disse mikrober kan leve i os, og nedbryde plast til fx føde, vil det selvfølgelig kunne give en fordel. Vi ved ikke om det sker endnu, men der er sikkert nogen mikrober som kan gøre det.

Det er helt klart malaria, den slår flest mennesker ihjel på årlig basis. Derudover er der en anden parasit, som hedder schistosomiasis eller sneglefeber, den er også meget voldsom parasit at få.

Som udgangspunkt tænker jeg at der ikke er nogle dyr som dør hvis de ikke har parasitter, men der er faktisk nogle parasitter som dør hvis de ikke har visse bakterier. Man giver derfor antibiotika som slår bakterien ihjel og dermed dørparasitten.

Hos husdyr kontrolleres parasitter med medicin men jeg ved ikke helt hvordan denne medicin påvirker miljøet. Hos husdyr er man nødt til at bekæmpe parasitterne, for at have god dyrevelfærd. Der er faktisk steder i verden hvor man slet ikke kan have husdyr, fordi parasitterne er resistente - så parasitterne betyder bestemt meget for vores husdyrs vækst og sundhed og især drøvtyggerne.

Ja absolut. Der er faktisk nogle meget interessante resultater fra Frankrig, hvor de har sammenlignet mund-mikrobiomet for mænd og kvinder som bor sammen. Det viser sig her at der er et meget tæt forhold mellem mikrobiomerne. De har derudover også undersøgt par som ikke bor sammen, og de kan også have meget ens mund-mikrobiomer. Så man kan bevise at der er en tæt relation mellem mikrobiomer, også selvom man ikke bor sammen.

Ja det kan man godt. Tit når folk tager til udlandet oplever de at have maveproblemer de første 2-3-4 dage, hvorefter det bliver meget bedre. Det skyldes at tarm-mikrobiomet ændrer og tilpasser sig. Nogle mennesker er hurtige til at ændre deres tarm-mikrobiom, mens andre er langsommere.

Ja det tænker jeg der er, fx piskeormen som vi arbejder med. Det er sådan med nogle ormeinfektioner, at hvis man har få orm, gør de ikke skade på kroppen, men har man mange orm er det klart at man bliver syg af dem. Så lidt parasitter kunne måske have en gavnlig effekt, men det skal være nogle helt bestemte parasitter.

Nej, i forhold til denne leverikte er der ingen risiko for at blive smittet videre. Men der er nogle parasitter (fx trikiner) som lever i kødet og derfor er det vigtigt at have nogle produktionsforhold som minimere forekomsten af disse. Hvis man fryser kødet eller koger/steger det, vil det slå parasitterne ihjel. Men der er ingen grund til at være bange for parasitter i det kød vi spiser i Danmark så længe at det ikke spises råt.

Absolut. Der er ingen tvivl om at det vi spiser påvirker vores mikrober.

Jeg har ikke smagt grib, men min fugleven Garry har smagt det. Han har grillet deres kæmpestore brystmuskler og han siger at det smager fantastisk. Man skal ikke være bange for at få deres parasitter eller bakterier, så længe man ikke spiser deres tarm eller slikker på deres ansigt, men spiser man bare rent kød bliver det ikke et problem.

Meget interessant spørgsmål. Vi ved det faktisk ikke, men miljø påvirker selvfølgelig folket. Samtidig er der mange store forskelle på hvilke mikrober vi møder i forskellige miljøer, så man kan ikke sige at mikroberne ikke påvirker deres adfærd. Det kunne være meget spændende at sammenligne folk som er vegetarer med folk som ikke er vegetarer og se om der er forskel på deres adfærd.

Ja, der er nogle folk som er laktoseintolerante, men som alligevel kan spise mælkeprodukter, hvilket skyldes bakterier og mikrobiomet i deres tarme. Tom Gilbert

Parasitter kan være med til at påvirke den mikrobiota vi har, og kan dermed være med til at påvirke bakterie sammensætningen som vi har i tarmen. Men jeg ved ikke hvordan de direkte skulle kunne påvirke fødevare intolerance. Peter Lindberg Nejsum

Vi har i Danmark ikke parasitter på den måde at vi hele tiden bliver smittet. Men hvis man er inficeret med parasitter, så skal man bare gøre noget ved det. Børneorm er jo en parasit som rigtig mange kender, og den skal man helt klart behandles for, for den smitter rigtig meget. Det samme gælder hvis man har lus.

Nej der er kommet meget færre parasitter med årene, og det skyldes at biodiversiteten i dyrene falder. Dvs. at parasitterne forsvinder når deres værter uddør. Det er i naturen. Hos mennesker er der også kommet færre parasitter fordi vi har fået medicin og fordi der er lavet forskellige tiltag som reducere parasitternes evne til at smitte. Hvis vi ser over de sidste 10,000 år kan man godt sige at der er kommet flere parasitter til fordi vi levere tættere på (hus) dyr og der er parasitter som smitter fra dyr til mennesker.

Det er et godt spørgsmål. Efter man har indtaget piskeormsæg vil disse klække og parasit larven vil bore sig ind i tarmvæggen og efter nogen tid vil immunsystemet begynde at reagere på parasittens tilstedeværelse. Denne reaktion kan måske være grunden til at betændelsestilstanden bliver reduceret og du derfor får det bedre.

Yes – this is because many microbes and parasites are unique to their host. And if the host goes extinct…so do they.

Most biologists say no. Viruses are not made out of cells, they can't keep themselves in a stable state, they don't grow, and they can't make their own energy. Although so-called recently discovered Megaviruses maybe challenge that idea..

A very very large number! But this is because what we call a microbe species is different to a normal species, as often microbes can switch in/out what genes they have in their genome. Which means although we may say 2 bacteria are the same species, if we look at what they can functionally do, they can be quite different.

I mentioned glutamate, which is a neurotransmitter, which is not the same as glutamine – which I think is what you refer to?

Yes we do, Helicobacter pylori is a great example. It can cause stomach ulcers in some people.

I believe only some plants have more genes than animals. Sometimes this is because many plants duplicate their genomes, which gives them extra copies that are free to evolve to fulfill more functions. I don’t know for sure, but I suspect that when plants have more genes than animals, it’s because they are required to have more biochemical pathways in order to live.

I believe that some people have argued that when you are nervous/stressed, your body will produce different hormones and other chemicals. These can affect all of your body, including your gut, and as such could modify the gut microbiome community to give you diarrhea. Although I suspect the physiological could also cause diarrhea without affecting the microbiome too.

Yes, but its a very short genome (humans maybe 16500 nucleotides, compared to our nuclear genome which is 3,000,000,000 nucleotides). And the mitochondria genome encodes very few genes, mostly these affect how energy is used in the body.

Wolves were (probably) changed to dogs through artificial selection driven by human choice. Specifically when humans first lived alongside the wolves that would eventually become dogs, they would have preferentially kept/bred any ‘wolves’ that had traits that were desirable to humans, e.g. more gentle behaviour. Not all wolves will have had these traits – it would depend which genetic variants were in the wolf population at the time of domestication. But every time a wolf was ‘kept’ because of some trait, it meant the specific genetic variant causing the trait was kept in the ’original dog’ genepool. And by combining different genetic variants found in different wolves by deliberately crossing ‘original dogs’ with different traits, slowly we would have built up an animal with more and more of these desirable traits (and genetic variants causing them).

So in summary, the genetic variants were probably present at very rare levels in wolves before humans tried to tame them. But no wolf had all the variants needed. And the creation of the dog was about mixing together the right kinds of wolves to get the right combination of all the genetic variants together in one animal.

Very tough question! But maybe one of the key findings is how tightly connected all the different lifeforms in an ecosystem are. And how if we affect one of them, we affect the whole community, and even the planet as a result. And this can have very catastrophic consequences. As for which ongoing project do I find most interesting, I think its probably studies into whether its possible that life could form elsewhere, whether in space (e.g. on comets) or on other planets.

This is the gut-brain-axis that I talked about. That specifically microbes in our gut can produce chemicals that affect our brain and nervous system.

I don’t think they can affect intelligence directly. But they can affect behaviour. And also of course if you have microbes in your gut that are very good at digesting food, that will release energy, that will allow your brain to work better.

Yes, this is possible at least within a species to make large changes, and is how for example faecal-transplant therapy works. Basically you give a patient antibiotics to clear out their original microbiome. Then you provide them with microbes taken from a donor, either as a pill, or a direct transfer. And the new community establishes.

But also every time you for example eat you will slightly modify your microbes. If you stop eating ryebread, this will mean you lose microbes that are very focused on digesting fiber. And other microbes will grow instead.

Fæcestransplantation er en behandling man nu bruger i Danmark hvis man har fået en bestemt bakterie infektion (Clostridioides difficile) og man ikke kan komme af med denne med almindelig antibiotika behandling.

I’m afraid I don’t know the full answer. It will definitely affect our gut microbiome, as any change in diet does this. But I don’t know what the consequences are.

I think its a combination of both. For example if you have gut microbes that are making you feel more anxious, this will condition how you then react in other situations.

Many people have it at a very very low frequency in for example their colon. But the levels are kept very low due to the other microbes in the gut, that are there because of what we eat. But for example when we (or an animal) dies, then the normal microbes often die out as the body is no longer eating and feeding, and that’s when microbes like Clostridium that evolved to digest dead meat, begin to increase in frequency. And then if something eats meat contaminated with large levels of Clostridium…then they can become infected unless they have a mechanism to deal with it (like vultures do)

Sorry, this is not something I know anything about.

Sorry, this is not something I know anything about.

En kost bestående af mange forskellige slags grøntsager og plante produkter (inklusiv fiberholdig mad) burde give en artsrig tarmflora som vi forventer er sundt og godt for helbredet inklusive det mentale

Yes, I try and eat more fiber (e.g. ryebread, which as an Englishman I naturally don’t enjoy). As its clear that fiber content helps promote microbes that then synthesise short chain fatty acids, and these can have many positive effects on us. See for example this link.

Yes there is. Epigenetic changes are genetic modifications that impact gene activity without changing the DNA sequence. And changes in gene activity can affect the microbiome. And the microbiome can also modify the genome through inducing epigenetic changes. Therefore they are all tightly linked together.

As far as I understand Wegovy acts to regulate appetite by increasing a person's feelings of fullness, while reducing their food intake, hunger and cravings. So while this will have a consequence on the gut microbiome (as people will eat less), this is more a side-effect than the actual driver of weight loss.

Unfortunately while it would be super to try this, the only faecal remains from dinosaurs are fossilized…so basically stone. No microbes surviving to be analysed!

Certainly, I would advise that if you do handle a wild vulture you clean your hands very carefully after! But there is probably no harm in handling it if you do that (as with any animal). If on the other hand you get bitten by a vulture…or have a cut/sore on your skin, then you might face a risk of infection.

I suspect its both cases. Most autistic patients suffer from gastrointestinal (GI) symptoms and I have read that gut microbial fermentation of plant-based fiber can produce different types of short-chain fatty acid (SCFA). And some of these may have a beneficial, while others may have a detrimental effect, on the neurological development of autistic patients. But of course it could be that patients with autism also make lifestyle (e.g. dietary) choices that in turn shape their gut microbes. So it’s a big circle.

Symbioses are where two (or more) lifeforms are completely reliant on each other, that is neither can exist alone. A good example is lichen, which is an algae and a fungus. Neither partner can exist without the other. Holobionts can involve partners that are not mutually dependent on each other. (although they can also be 100% codependent, so a symbiosis is a form of holobiont).

I’m afraid I don’t know much on this, but if I had to guess, I would assume that the following could explain it. I speculate that as a result of COVID-19 infection, there could be an effect on our gut microbiome. For example COVID-19 changes our body temperature, but also can modify what we want to eat (e.g. it changes our taste and sense of smell sometimes). Both could lead to modifications in our gut bacterial community. And as gut bacteria can affect the brain…there could be a knock on effect. Probiotics are often talked about when people wish to change the gut community. E.g. after antibiotic treatment, some people advocate eating foods like yoghurt can be full of live microbes, in the hope these help both establish the gut microbiome, and in doing so also prevent opportunistic infection of the gut by problematic bacteria.

Certainly some researchers argue this could be the case. See for example this link.

One of the main success I have heard about is with regards to controlling infection by Clostridium difficile. You might find this article interesting on the topic.

We can definitely modify our diet to change our gut microbiome in a way that is positive. It’s a complex topic, and I personally believe that not everyone will react the same way to different foods. This article provides some suggestions.

Generally there is consensus that eating fiber rich foods (e.g. rugbrød) are particularly good for you.

As for whether the microbes from our dogs and cats are good…that’s a harder question. Definitely dogs and cats can carry dangerous microbes. For example if a dog has eaten faeces, you probably don’t want to get those microbes on a cut, or in your mouth. Especially if you have a weak immune system. On the other hand, there is evidence that it is healthy to be exposed to a diverse range of microbes (and in fact as Peter mentioned briefly, we can have autoimmune diseases occurring when our lives are too sterile). See this link for example.

Not all of them, as there is a tight relationship between an animal’s genetic variation, and its microbiome. But certainly some microbes are found in many species, suggesting they can be transplanted between animals. But many others will be much harder to transplant (for example they may be pathogenic to one species, thus cause an immune response, but harmless in another).

This is a complicated question! At a very general level, diversity is good for ecosystems, whether microbes in the gut, or plants in a forest, or animals on a savannah, or parasites in animals. The more diverse an ecosystem, the more resilient it is to change. The less diverse, the easier it is for e.g. diseases to enter a system, or invasives affect it (this is why many argue against monocultivation strategies, where the same crop is grown in huge amounts over large areas). In the case of microbes, the more diversity there is, the more interaction with each other and the environment, and thus the more diverse the range of outcomes can be. Also the more diverse the microbes, the less chance any one can dominate, thus mitigating the size of any outcome. For example if you only have one bacteria dominating that gut, and it is pumping out chemicals that might affect your brain to give you depression…it will have a much bigger effect on you than if that bacteria is just one member of a much more diverse community. As in that case there will be fewer of the bacteria, thus less chemicals produced.

With regards to the second part of your question, there is concern right now that because farmed animals and plants are raised in very controlled conditions, with minimal surrounding biodiversity, they are much more susceptible to disease and other problems like (in the case of plants) drought etc. So it could be argued that by making the ecosystem around them in general, and the microbes in them, more diverse, they might be more resilient/able to find more solutions to the challenges they face.

De har forskellige strategier. De kan blandt andet ændre deres overflade sådan at de antistoffer som kroppen laver mod parasitten ikke virker mere. Så laver kroppen nye antistoffer ift. den nye overflade på parasitten, men så ændrer den sig igen. En anden strategi er at påvirke immunsystemet på en måde så det ikke er så aktivt og ikke kan bekæmpe parasitten og en helt tredje måde er at dække sig til med værtens molekyler så immunsystemet ikke kan ”se” parasitten.

Its very easy to modify it to some degree through diet changes. See above answers on the topic. But there will be a limit how much you can change it, determined by your genetics. But for the purpose of improving your health, a lot can be done with diet alone.

The hypothesis that was proposed relates to the fact that C. perfringens has genes that synthesise biofilm related proteins such as UDP-glucuronic acid epimerase. This lead to the hypothesis that it might not pose pathogenic risks but instead offer colonisation resistance against other pathogens. However, note this is only a hypothesis.

We don’t know, although they could have co-evolved.

It would be great to do that. Practically however…its very hard to get permission to do anything with pandas, especially invasive things like that.

Definitely generation time is relevant. As the faster the generation time, the faster evolution can happen. As for transplanting microbes, this is harder given the fact the genomic variation specific to any species has a big shaper on which microbes can live in it. This is why we think pandas have not yet changed their gut microbiome enough yet…they haven’t had enough time to change their genome to make this possible.

Great question. I’m not sure there is any proof of this…but it seems like an intriguing possibility! Definitely we know that the same kinds of microbes can often cause similar behavioural change in different kinds of animals (e.g. the happy chickens have similar microbes to happy rats). So its very plausible!

This does seem to be in interesting possibility in light of recent medical findings linking the two. See this link for example.

I’m not sure plan eaters are always less aggressive. The most dangerous animals in Africa are often referred to as buffalos and hippos (and of course…humans!). But certainly it could be argued that there is an overall tendency to be more docile if you have a higher butyrate production.

Its not 100% clear if they are alive on the facial skin, as opposed to routinely being deposited there via the gut. Vulture nests are (apparently) a horrid mess of faeces, and some species also defecate deliberately on their legs. Possibly as a way to cool down as the water in the faeces evaporates.

Vi ved fra forskningen at man har et dårligere vaccine respons hvis man er inficeret med ormeparasitter. Det gør ikke at man ikke er beskyttet mod f.eks. COVID-19 men man er ikke så godt beskyttet. Da ca. 1 milliard mennesker er smittet med orm undersøger vi om vi kan tilsætte specielle hjælpestoffer til vaccinerne sådan at de virker lige så hos mennesker med orm som dem der ikke har.

I’m afraid its not an area I know a lot about, but certainly we are starting to learn a lot about how diet can be linked to changes that can affect mental health. So its certainly possible to eat to try and improve your feelings.

There are ongoing research in Denmark investigating if fecal transplantation can improve mental illness.

I’m afraid I don’t but this article seems relevant.

Der forskes i dette område pt.

No, the diet and other conditions were completely controlled (actually I think the two types of chicken live together). So we know the difference in the gut microbiome is not an effect of diet or the environment. Purely the chicken genetics!

Initially through seeding during birth from e.g. the vaginal canal and areas of the body near that. And then building on this the microbes they are exposed to in the early days of their life, e.g. through mouth-skin contact when breast feeding. As a consequence of the first point, there are concerns that babies born by caesarean may be missing out on initial good microbes, hence there are some arguing that newborn babies delivered this way should be immediately inoculated with microbes collected by swapping around the mother’s genital region. A quite comprehensive general article on the topic is here.

See answer above.

It’s certainly possible given the demonstrated links between these conditions and gut microbiomes.

There are 2 different sources of enzymes involved in digestion. Some are human produced. Others are produced by the microbes in our gut. Both sets do different kinds of digestive processes.

Yes I believe so. Much of the study of the specific microbes in our guts involves sequencing their genomes, to see what enzymes they produce, and thus what the effect on food is. And in some cases, the microbial enzymes do some initial digestion, and then human produced enzymes digest the derivative products further.

I don’t know about this topic but a quick search suggests yes, it may have an effect. See this link for example.

Yes, some people believe this might indeed be possible in the future. It certainly seems plausible to me.

Both experiments were selected on only one principal characteristic, that is how scared (or not scared) they were of humans. Our data shows that one reason that may have driven these differences was their gut microbiome. Which suggests that actually what was being selected on was genetic variation shaping something like the immune system or another parameter that could lead to differences in the gut microbiome.

You can change your gut microbiome considerably. However we know that your early life gut microbiome can also shape your immune system in a way that means that someone who was exposed to certain microbes early in life may not respond the same way to re-exposure later in life, than someone who never was exposed to them early in life.

Given that we believe that most genetic variants relevant for early domestication did exist in the ancestral species’ population (although at low frequency – see answer above (29)) and given we believe it was genetic variants relevant to shaping the gut microbiome that were probably first selected on (as they can give quick behavioural changes) – I would argue the genetic change allowing for the microbe community came first. But this is a different set of genes than those that today encode major behavioural differences. So in summary I propose the order went this:

1. Genetic variant in wolf that lived among humans that allowed possibly beneficial gut microbiome
2. Beneficial microbiome enters wolf once they live alongside humans (thus get exposed to new microbes)
3. This changes the behaviour sufficiently that over the longer term other genetic variants can be selected on to change the behaviour in ways that do not need microbes.

I’m not sure anyone has hard evidence on what they do, although see answer above (49).

I believe there are many studies showing there are sex based differences in the gut microbiome. I am not sure whether any one has looked at the behavioural consequences of this yet (but its not an area I know a lot about).

You are correct. But I don’t think at this point they know the exact cause of the gut microbiome change. Note that it could be a mix of change in diet but also change in the hormones of the bear itself, as an animal’s hormones can shape its microbiome.

Most fish ate other fish, invertebrates etc.

I suspect its not great to let a dog eat any human food as they did not evolve to eat them. But there are probiotics sold that allegedly are good for dog behaviour. See this link for example.

However not all probiotics sold may have strong evidence behind their efficacy, so I would always when considering probiotics keep a critical mind.

Yes, both. See answers 64, 68

Great question, and yes, links have been shown – it seems to be a very active area of research.

This is to me a really perplexing question. Apparently there are reports that pandas in both the wild and captivity can (and occasionally do choose to) eat meat. So why they prefer not to is really quite bizarre. Maybe its just because its easier to catch bamboo?

Probably nothing good…there is evidence that both chemicals (pesticides but also other things) and food processing modify the gut microbiome. And typically so it produces less of things that are good for us, like short chain fatty acids. See previous answer 49 for good diet suggestions.

I’m not sure if this has been studied in detail, including if its purely a matter of taste (e.g. they are happy to do it), or if they also have particular microbes that help them deal with it.

See answer 49.

Some Lactobacillus are milk bacteria. There are however many kinds. But we don’t get them from fresh milk. Rather they were initially named this because they were found to be in fermented milk - so they are good at colonizing and utilizing milk.

In general bacteria that even appear closely related can have very different genes in their genomes, and thus have very different functional consequences.

I don’t think there is enough data on the topic yet, as its such a new area.

Probably both cases. There are some bacteria that get nothing out changing the host’s behaviour. But others may get a behavioural change that benefits them (even if its just making sure the host is better at hunting, so provides the bacteria with food).

Definitely there needs to be both a microbe that produces a metabolite, and a host gene encoding something that response to the metabolite. I guess typically its conventional genetic variation. But in some cases certainly there could be a role of epigenetics.

I would imagine eat a diet that promotes as many good bacteria as possible. See this link for example.

I think its hard for most people to understand it as they don’t have your extensive knowledge of the biology and biochemical consequences of Lactobacillus….

As mentioned in a few other answers, I think it probably varies by situation. We can never know the true answer in most cases as we can’t travel back in time. But we can at least propose possibilities.

I think this is unlikely as antibodies would act to remove Clostridia from the vulture. But we see, even in zoo vultures that are not continually exposed to Clostridia, that Clostridia remain. Suggesting there are NOT antibodies being produced to remove it.

Absolutely. Modifying (or linking) any behaviour to microbes, and thus developing treatments using microbes is very tricky. And hence if its ever going to be done its probably best its done by people trained in psychiatry, behaviour etc. My point was just to suggest its something that could be considered. There are also many ethical considerations. E.g. if we know that diet changes microbes, and these change our behaviour….is it ethical to change diets to change behaviour without the consent of the person eating the food?

I’m afraid I don’t know as I don’t work on the topic. Maybe this article is useful.

I’m afraid I don’t know, I don’t actually work on humans.

Yes. Here is a scientific review on the topic.

I believe it could be both, as there are many different microbes involved. To further complicate it, even if two different people are given the energy directly (not through food or with microbes involved) differences in their own genomes could affect how they react to the energy as they may have different basal metabolic rates. Its very complex…

This article suggests that yes, that could be the case.

Yes. If you are sick with a relevant reason, the Doctor can get it done. If not there are companies that do this. I don’t know if there are any in Denmark but I saw this one in the UK. So probably Denmark has companies doing it.

I would say yes, there is a risk. Whether its a big risk is another question…we really don’t know enough about how in humans, where we have so many other complicating factors than animals), how the gut and behaviour interaction really works.

I think as in the above answer (102) while in theory yes, in practice humans are so complex it might not be that simple.

Good question. As mentioned in answer 40, there is evidence that microbes can lead to epigenetic changes, that is the turning on/off of genes we already have. And at least in one study it was shown that occasionally bacteria can even transfer genes into the human genome.

Apparently in a positive way. Exercise is always good. See this link.

This is because they still haven’t had time to change their own genomes, in a way that would allow their microbiomes to change. This highlights how hard it is to effect a major microbiome change…as it often requires changes in the host genome first.

Definitely not (in my opinion). See answer 95

No idea. But sounds like an awesome thing to test.

I suspect its an idea under consideration, but as you can imagine people are naturally quite resistant to the idea of eating someone else’s faeces.

See answer 41

Basically because different microbes release certain chemicals into the body that can affect us. See this link e.g.

Super question! We don’t know. But my guess is they will NOT lose the ability as their genome allows them to both defend against really bad microbes in rotting carcasses, but also select for microbes that help. But of course if they don’t have exposure to the microbes they need…that would be tricky.

One of the key mechanisms is they help the bear generate enough fat to survive the winter when they are preparing to hibernate. See this link.

See answer 66

Yes, although I don’t know a lot about it and one would need to be careful. Maybe this page is helpful.

See answer 98

Generally organisms adapt to be able to use potential resources, so they don’t have to compete so much with each other. Plants were an unused resource, and once animals adapted to it…those that were successful benefitted.

Definitely plant digesting microbes. As both plant eating arthropods need them to digest plants. But also because if plant digesting microbes didn’t evolve…the planet would have been buried under all the dead (and undigested) plants…

And yes, its an intriguing idea that plant eating tetrapods might have been helped by eating plant eating arthropods. As that would expose them to the gut microbes of the arthropods. And that would allow a situation where natural selection could act on any tetrapods that were able to somehow use those microbes to eat plant.

We have different microbes in different parts of our intestine. As a general pattern the diversity of microbes increases the closer we get to the colon. So if you have some of your intestine removed…depending how much and which bit, that could have an effect.

To clarify, I said that there is evidence in flies and rodents that this is the case. And it would be interesting if this was the case in human too. I would guess if it’s the case it might be we select on similar microbes, but an argument could be made for the reverse (e.g. if we were to select for a partner with a very different immune system…so as to make sure babies born have as diverse an immune system as possible) – then actually in that case it would make sense to select for a diverse microbiome (as immune system has a big effect on microbiome).

This could well be the case.

Probably very little, as epigenetic changes rarely last more than 1-2 generations, which is too short for most evolutionary consequences.

I think the theory is pretty similar for both. Too much hygiene leads to too active immune system, leading to autoimmune disease, allergy etc.

Its an interesting idea. There is some evidence that there is a genetic basis to A/B type e.g. via the Per3 gene. If correct it suggests that principally the cause is due to the genome of the person. But I wonder if it would be possible to mitigate the effect by transferring microbes that could increase activity. If you guys try it out…let me know what you find out

Yes, we do this a lot as we often give animals antibiotics before we give them a faecal transplant in e.g. behavioural studies. What microbes an animal (including humans) gets after antibiotics depends on what microbes they are exposed to after. So if you take an omnivore person, and sample their microbiome. Then give them antibiotics. Then only give them vegetarian food after, they will end up with a different microbiome. On the other hand, if they get very similar food before and after, probably the microbiome will be very similar.

In general dogs seem to be much better at dealing with microbes that would make us sick if we ate them. My dog drinks from the river all the time and doesn’t get sick. If I did that…it would be horrible results.

I guess there are 2 reasons why this is.

First, dogs just genetically may have a better immune system for these kinds of microbes

Second, its definitely true that if you are continually exposed to microbes, you can get used to them. E.g. if I try to drink river water every day, I will probably (after some horrible few days) adapt to it. As my gut microbiome will change, to become more resilient to it.

Good question. It’s not my area of expertise, but I would guess that a good diet change will have more of an effect than taking pills with only one microbe in them. As a diet change will lead to many more microbes changing than a single pill.

Certainly, some people believe this. See this page.

We are quite capable of eating insects – many populations do, including in African where we evolved.

See answer 87

Det er et godt spørgsmål som ikke er belyst men vi kunne måske spørge Andreas Mogensen om det er noget han vil være med til at undersøge.

Når biodiversiteten falder rammer det dobbelt så at sige fordi parasitterne også forsvinder og dermed bliver stabiliteten at økosystemet nedsat

Det tyder på at hageorm og piskeorm kan være gavnlige for vores sundhed – hvis og kun hvis – at vi ikke har for mange af dem. Hvis der er mange bliver man syg.

Det skyldes at spolorm smitter via æg i afføringen men æggene skal først modne i miljøet i mindst 4 uger. De er altså ikke smittedygtige lige når de kommer ud. Når vi derfor bruger wc ender vores afføring på et rensningsanlæg hvor parasit æggene bliver dræbt og livscyklus stoppes. Dette er imod sætning til børneorm hvor æggene meget hurtigt bliver smittedygtige (inden for 24 timer) og derfor er brug af wc ikke effektiv til kontrol. Tilmed er parasitten så smart at frigive et stof der gør at det klør analt og derved får man let æggene på fingrene.

Spolorm er lidt mere hårdfør en piskeorm og kan findes i områder som er for tørt til piskeorm. Så det kan være forklaringen. Men ellers kan det også skyldes at prøverne simpelthen er så gamle at de er forsvundet eller hvis vi havde mulighed for at undersøge nogle flere at de ville dukke op. Men generelt er tørt miljø det værste for en ormeparasit fordi de opholder sig i miljøet som en del af deres livscyklus og de derfor let udtørrer og dør.

Sådan globalt ved vi det faktisk ikke. Men et studie viste at biomassen af parasitterne i en marsk var større end fuglene i området og et andet studie viste at bare en parasit art havde lige så stor biomasse som sneglene som parasitten lever i. Dvs. at i løbet af sneglens liv så frigav sneglen så mange parasitter at biomassen af parasitterne var lige så stor som sneglen selv.

Mig bekendt er der ikke vist en sammenhæng men der er en anden parasit, toxoplasma hvor man mener at der er en sammenhæng.

Hvis du mener om der er parasitter som slår os ihjel så er det et stort JA! Malariaparasitten alene har 500.000 menneskeliv på samvittigheden hvert år. Selv en parasit som hageorm som man siger ikke er så farlig slår omkring 50.000 mennesker ihjel om året.

Det kommer an på hvilke vesikler det er. Men de vesikler som frigives fra en ormeparasit indeholder orme DNA/RNA og det vi undersøger er om dette DNA/RNA optages af værten for på den måde at manipulere immunresponset så parasitten kan overleve.

Godt spørgsmål. Trichuris suis er grisens piske orm og den er derfor ikke tilpasset til mennesket. Derfor overlever den kun midlertidigt i vores tarme og dør herefter fordi den er kommet ind i ”den forkerte” vært. Derfor er immun stimuleringen kun midlertidigt og man skal derfor gentagende gange have piskeorm hvis man ønsker en vedvarende effekt. Det er i modsætningen til menneskets piskeorm om tyder på at overleve i måske flere år i tarmen.

Ja, det tænker jeg bestemt, og det er et område som der forskes i for tiden.

Ja, det er en rigtig god tanke. Hvis vi kigger langt tilbage i tiden (+100.000 år eller mere) så må der have været et tidspunkt hvor der var et værtsskifte. Altså at mennesket fik piskeorm fra gris eller omvendt. Men hvis vi ser på nyere tid, som vi ser på i dette studie, så er de udviklet til 2 arter og vi ved at grisens piskeorm kan inficere mennesket men de har svært ved det og overlever ikke særligt godt. I dette tilfælde er den mest oplagte forklaring derfor at 1) æggene er forvundet (nedbrudt) fra prøverne eller vi ikke har undersøgt nok eller 2) at der ikke var menneske piskeorm i Jordan. Generelt ser man ikke mange ormeinfektioner i Mellemøsten fordi det er så tørt et miljø og i et sådan dør æggene inden de når at modnes og smitte nye mennesker.

Ift. hårormen og fårekyllingen så ved jeg ikke præcist hvad der sker men da den er så stor tænker jeg ikke at det er fordi den kommer op i hjernen. Det er mere sandsynligt at den udskiller et hormon eller tilsvarende molekyler som påvirker fårekyllingens hjerne.

Forsøget med mus lavet som blindet forsøg sådan at dem som undersøger hvor raske/syge musene er ikke ved hvilke test gruppe de tilhøre så man som forsker, ikke kommer til at påvirke resultatet. Dobbeltblindt forsøg bruger man hos mennesker hvor man ikke ønsker at forsker og forsøgsperson ved hvem der er med i test gruppen og kontrolgruppen. Det skyldes igen at man ikke ønsker at forsker skal påvirke resultatet men heller ikke personen som er med i undersøgelsen. Det lyder umiddelbart underligt at personen som er med i undersøgelsen skal kunne påvirke resultatet men det skyldes den såkaldte placebo effekt, altså at man kan få det bedre selvom at men f.eks. kun får kalkpiller som i princippet ikke burde have en gavnlig effekt. Placeboeffekten er et fantastisk spændende område som understøtter hvor meget vores psyke påvirker vores fysiske sundhed.

Se svar til sp 145

Det er et godt spørgsmål. På den enes side hvis man får dårlig og tynd mave pga. stress kan orm som lever i tarmen måske bliver ”skyllet ud”. På den anden side – hvis man er stresset påvirker det hele vores krop inklusiv vores immunsystem og vi kan derfor have svære ved at bekæmpe infektioner inklusive parasitter og jeg tænker at det nok er den mest sandsynlige konsekvens af stress.

Rigtig god pointe! Det mest 'naturlige’ vil være at give vesiklerne igennem tarmen for det er der ormen lever og det er noget som vi meget gerne vil undersøge. Som indledende forsøg er det lettest at give dem via en sprøjte (lidt som en vaccine) og derfor startede vi med det men det kan være at effekten er bedre hvis de gives til tarmen (via munden).

Per definition er parasitter skadelig for værten for ellers vil vi kalde det for mutualisme hvor begge organismer har fordel af samspillet. Men som nævnt er det ikke så sort/hvid. Mange af os har nogle parasitter, Demodex, som lever på vores hud. Det bliver stadig diskuteret om de gøre skade eller ej. Så er det en parasit? Og hvis de ikke gør skade, men at vi mennesker ikke påvirkes negativt, hvad skal vi så kalde dem? Og kan det være at de faktisk gør noget godt så det er et mutualistisk forhold?

Your gut microbiome changes constantly in light of what you eat, after you go to the bathroom etc. Also you have microbes both in the gut content, but also in the lining of the gut. When you empty your gut as mentioned here, the lining microbes remain and will quickly recolonize the gut content next time you eat.

Generelt har parasitter en meget negativ effekt på vores sundhed! Men nogle parasitter kan i bestemte (små) mængder have gavnlige effekter, f.eks. i forhold til sygdomme som er karakteriseret ved kronisk betændelse (inflammatoriske sygdomme). Det er et forskningsområde område som vi er meget optaget af i disse år.

Det korte svar er: Jo, det er det!

The world would have no life left. All life depends on microbes. Plants can’t grow without them. Animals can’t eat without them…

De parasitter som primært er forsvundet de sidste 70 år er spolorm og piskeorm. Det skyldes at de smitter via afføring, og smitten stopper derfor når man indfører toilet fordi æggene skal ligge og modne i miljøet før de er smittedygtige. Det er i modsætning til børneorm som laver æg som smitter meget hurtigt (inden for 24 timer) og da det tilmed klør når man har børneorm får man let smittedygtige æg på fingrene som man får i munden når man f.eks. spiser eller børn putter fingrene i munden.

Det kommer an på hvad du mener med farlig? Man kan dø af de fleste parasitter hvis man har mange af dem. Oksebændelorm giver som ofte ikke så mange symptomer hos mennesker (hvis man har få).

Der er mange af de samme molekyler som der er i almindelige celler, dvs. bl.a. DNA, RNA, proteiner og fedt.

Det kan man gøre på forskellige måder som du kan læse om på siden her.

Godt spørgsmål. Det ved jeg faktisk ikke. Man har dog fundet at børn som har ormeinfektion klarer sig dårligere i skolen. Om det så skydes en direkte effekt på deres hjerne eller om det skyldes at de føler sig småsyge hele tiden og derfor ikke kan følge så godt med i skolen, ved man ikke.

Jo, nogle parasitter gør faktiske at man har forøget risiko for at på allergi

Answered in 44

Not that I am aware of but I have not looked in to it.

Det er et svært spørgsmål at svare på. Hvis man får meget sukker vil man favorisere bestemte bakterier og muligvis så en mindre varieret bakterie sammensætning i tarmen. Men det kommer an på hvad man i øvrigt spiser.

I et studie fra Sydamerika fandt man at mennesker som havde parasitter havde et bedre multiple sklerose forløb end dem som ikke havde parasitter.

Malaria er i den grad skadelig for mennesker! Jeg ved ikke hvordan malaria påvirke myggen direkte men mennesker som har malaria er i større risiko for at blive stukket af myg så på den måde hjælper malaria parasitten måske myggen til at få noget at spise. Og et mere morbid eksempel er, når man ser historisk på det, at mennesker (eller vores forfædre) som havde malaria var i større risiko for at blive spist af andre dyr.

Godt spørgsmål. Det er klart et spørgsmål om balance. Hvis man er sund og rask vil man ikke give parasit vesikler fordi man netop ikke vil nedjustere immunsystemet men har man et overaktivt immunsystem som giver kronisk betændelse kan det være nødvendig at nedjustere immunsystemet og det er faktisk det man gør med forskellige typer medicin når man f.eks. har tarmbetændelse. Lupus, psoriasis og andre inflammatoriske sygdomme. Spørgsmålet er om vi også kan bruge stoffer fra parasitter i fremtiden.

Trikiner kan også nedsætte inflammation men det er aldrig noget som man vil bruge da Trikiner er en meget farlig parasit at få og når først man har fået den parasit så bare man rundt på den resten af livet. Heldigvis har vi ikke haft trikiner i Danmark siden 1940erne.

Jeg ved det ikke men kan forestille mig at plastik mest har en betydning for de øvrige dyr i vores miljø men derfor også indirekte på parasitterne. Men det kunne være spændende at undersøge.

See answer 36

Thousands of years of artificial selection by humans.