Response to Prebiotics Depends on Your Existing Gut Bacteria

This is a small, but I thought really interesting, study and I guess I’m not alone in finding it significant:  it was published in a premier medical journal, Gut.[i]  It’s a great illustration of the complexity of gut biome optimization because of the individuality of every person.  We don’t even yet know what a “healthy” microbiome looks like, let alone how each component affects each other and our response to diet and supplements.

These researchers’ results show that the composition of the gut bacteria changes the way the person responds to the addition of prebiotics (in this case, inulin) to the diet.  They took the fecal microbiota from  4 people with obesity and used it to inoculate mice (who’d been treated with antibiotics to wipe out much of their gut bacteria).  The mice were fed a high fat diet which was supplemented with the prebiotic, inulin.  The response to the inulin completely depended upon which person’s bacteria the mouse was given. Two donors’ (donor 2 and 3) microbiota led to no response to the inulin; the other two mice, with donations from 2 other people (donors 1 and 4), showed metabolic improvement, particularly in the mouse with donor 4’s microbiota.

The presence of certain genera of bacteria predicted response: “Barnesiella, Bilophila, Butyricimonas, Victivallis, Clostridium XIVa, Akkermansia, Raoultella and Blautia correlated with the observed metabolic outcomes…,” such as a decrease in adiposity.

A group of obese individuals, including the 4 people involved in the mouse study,  were then supplemented with 16 grams per day of inulin for 3 months.  Metabolic and microbiota changes, similar to what was seen in the mice, were seen in donors 1, 2 and 3.  Globally, responders to the inulin involved in the study showed “…an increase in Bifidobacterium species and Butyricicoccus and a decrease in Collinsella, Barnesiella, Akkermansia and Bilophila.”[ii]

The conclusion that can be drawn:  “These findings support that characterising the gut microbiota prior to nutritional intervention with prebiotics is important to increase the positive outcome in the context of obesity and metabolic disorders.”  That is, a certain profile of gut bacteria may mediate the metabolic benefits of prebiotics on those with obesity – and of course, you can reasonably extrapolate that it’s likely that a similar patterns would be seen in everyone, obese or not.  Different people will respond differently to dietary changes:  the interactions between diet and gut bacteria are highly personalized.

It has already been established in prior research that in healthy adults, eating a high fiber diet will determine the benefits of supplementing with an inulin-type prebiotic.  This, of course, once again hammers home the point I’ve stated about a billion times on this blog:  eat your fruit and vegetables!

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[i] Rodriguez J, Hiel S, Neyrinck AM, et al. Discovery of the gut microbial signature driving the efficacy of prebiotic intervention in obese patients. Gut. 2020; doi: 10.1136/gutjnl-2019-319726.

[ii] https://www.gutmicrobiotaforhealth.com/baseline-gut-microbiota-may-determine-inulin-effects-on-weight-loss/