authorities do not require them for probiotics as they would for medicines .
There ’ s a lot of snake oil out there . For most people , it ’ s probably harmless , but if you are immunosuppressed , it could be dangerous : Even beneficial bacteria can cause great harm if your immune system does not function properly .
Don ’ t get me wrong , I think there are many promising findings , but this field is very much in its infancy . I ’ m much more enthusiastic right now about whole-food approaches that adjust people ’ s diets to include more fermented foods — a source of beneficial bacteria — and the fibers that many beneficial members of our microbiome need to survive . And this , everyone can already do .
Have you done any experiments that show such a diet can improve mental health ?
We ’ ve just done a small study with what we call a psychobiotic diet . Kirsten Berding , a German dietician who did a post-doc in my group , took a group of people with bad diets who were stress-sensitive — namely , our student population — and put them on a one-month diet to really ramp up fermented foods and fibers to the benefit of the microbiome . What we showed was that the better individuals followed the diet , the greater the reduction in stress .
The study wasn ’ t perfectly blinded , because people knew what they were eating , but they didn ’ t know what they were eating it for . And this was just the beginning : We ’ re now doing a much longer study trying to really untangle this .
We ’ ve also done a small randomly controlled study with a polydextrose fiber that was shown to improve the performance of healthy volunteers on a range of cognitive tests .
Obviously , more work of this kind is necessary . But in this case , I don ’ t think we should wait for that . Think about the experiment where we ’ ve transplanted microbes from young to old mice , for example : I ’ m not advertising poop transplants for aging adults . What we ’ ve found is that the more diverse your diet , the more diverse your microbiome , and the better your health when you get old . If you look at the beige , bland food served in many nursing homes and hospitals today , that is not the kind of diet that helps people to maintain a healthy microbiome and therefore a healthy brain .
We ’ ve done a study in mice where we adjusted their diet to contain much more inulin , a fiber that we know supports the growth of beneficial bacterial strains , and found we could dampen down the neuroinflammation that is often associated with cognitive decline in aging . This fiber is present in our everyday diet — there is a lot of it in vegetables like leeks , artichokes and chicory . So perhaps if you ’ re thinking of having a midlife crisis , forget about the motorbike and start growing vegetables .
This is all in healthy patients . Do you think the diet might also help people with mental health issues ?
I do , but we need to test it , of course . An earlier study of ours showed that students born by C-section , who missed out on some of the microbes that newborns acquire during vaginal birth , had an elevated immune and psychological response to both chronic and acute stress , in line with our findings in mice . It would be very interesting to test if a psychobiotic diet might benefit them .
As I said , many psychiatric disorders are also associated with inflammation and other problems in the gut . Of course , this relationship works both ways , and it ’ s not always clear to what extent the irregularities in the gut are the cause or the result of the mental issues — or whether it ’ s a bit of both . But if we can show a healthier microbiome can improve mental health , that would be great news .
This is what ’ s appealing about the microbiome : It ’ s probably more modifiable than the rest of our body . If we understand how it works , that might give people more options to improve their health , even if they didn ’ t have the best start , microbially speaking . That ’ s what we hope to achieve .
This article was first published in Knowable Magazine . Read the original article here .
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