A new concept in the microbiome space, fermented human milk sugars:

Human milk sugars, which can be cultured through yeast fermentation–in a similar process to making biofuel or brewing beer–seemed like a good fit. In breastfed infants, the human milk sugars help build up bifidobacterium in the gut, one of a few bacteria that can digest the complex sugars. The bacteria help make the gut more acidic, which “prevents E. coli and bugs like that from getting an early foothold,” says David Mills, a professor of food science and technology at the University of California-Davis who studies the oligosaccharides. “It’s telling the immune system what’s, in a sense, a good bug and a bad bug.”

Also interesting comments on junk food.

Eating junk food quickly affects the gut microbiome; in one study, a group of rural Africans who temporarily shifted from a healthy diet to burgers and fries showed both a marked change in gut microbes and an increase in biomarkers of cancer risk after only two weeks. In addition to shifting to a healthier diet, the scientists say that probiotics–such as bifidobacterium, which is added to some foods like yogurt–might help. And though there’s little research to back it up so far, the theory is that a supplement of human milk sugars, part of a class of ingredients known as prebiotics, could help those probiotics work better.

That is from Fast Company’s article, The Next Thing In Gut Health Is Going To Be Sugar Made From Human Breast Milk by Adele Peters,  online link here

Here is a Link to the referenced Nature Article 

For more on probiotics gut health, see our pages here, here and here.