This study of some healthy Dutch people still concludes that having a higher diversity bunch of bugs in your gut is healthier. Not exactly an intuitive result, compared to what people probably would have thought until recently:
This DNA analysis made it possible to examine which factors impact the diversity of the microbiome (the intestinal bacterial community unique to each of us). And that appears to be many. Wijmenga says, "You see, for example, the effect of diet in the gut." People who regularly
consume yogurt or buttermilk have a greater diversity of gut bacteria. Coffee and wine can increase the diversity as well, while whole milk or a high-calorie diet can decrease it.
"In total we found 60 dietary factors that influence the diversity. What these mean exactly is still hard to say," explains UMCG researcher Alexandra Zhernakova, the first author of the Science article. "But there is a good correlation between diversity and health: greater diversity is better."