Gut microbiome uses breast milk to promote healthy infant growth, reports a new study published in Cell last week. Researchers from the Washington University School of Medicine in St. Louis have found that breast milk sugars promote healthy infant growth through interactions with gut microbiome. Human milk is composed of numerous bioactive substances, including human milk oligosaccharides (HMOs). Analysis of HMOs from 6-month-postpartum mothers in two Malawian birth cohorts revealed that HMOs containing sialic acid residues, which have been implicated in proper brain development, were far more abundant in the breast milk of mothers with healthy versus stunted babies, suggesting that these breast milk sugars may promote healthy infant growth. To determine if this was the case, the researchers established animal models that allowed both diet and the gut microbiome to be manipulated. They colonized young germ-free mice with a consortium of bacterial strains cultured from the fecal microbiota of a 6-month-old stunted Malawian infant and fed recipient animals a prototypic Malawian diet consisting of corn, legumes, vegetables, and fruit, which on its own is insufficient for healthy growth. With both the diet and microbiome mimicking those of undernourished Malawian infants transitioning to solid foods, the researchers then tested the effects of sialylated sugars. Sialylated bovine milk oligosaccharides (S-BMO) were isolated from whey and fed to the animals. Remarkably, the animals showed substantial improvements in growth, with increases in lean body mass and bone volume as well as metabolic changes in the liver, muscle, and brain suggesting improved ability to mobilize nutrients under diverse conditions. Crucially, these effects depended on the presence of the gut microbiota. This study lays the groundwork for identifying the components of breast milk that are needed for infant health and how they interact with the gut microbiome and other dietary components. One possible application that may stem out of this work is improving infant formulas as well as therapeutic foods used to treat undernutrition, both of which are currently based on cow’s milk and are therefore deficient in sialylated sugars.
Just as the emerging medical field around the human microbiome seeks to fight disease by adjusting the balance of bacteria in the body, Indigo, a Cambridge, Massachusetts-based startup is manipulating the composition of bacteria in plants to grow healthier crops that ultimately produce more nutritious food. The idea is that crop seeds coated with a custom-crafted brew of bacteria and fungi can better resist high temperatures or drought conditions. The results so far: a 10 percent increase in crops yields across the board. Indigo—called Symbiota at its launch—is trying to reintroduce microbes to plants that it says have been lost through the tools of modern agriculture—fungicides, pesticides, herbicides—in the same way that the overuse of antibiotics has disrupted the human microbiome. The company is able to capitalize on a handful of new technologies that have only recently matured. By sequencing the genomes of organisms found in thousands of plant samples taken from all over the world, Indigo’s scientists have created a database of more than 40,000 individual microbes. Using machine-learning algorithms, they identify specific organisms likely to be beneficial in certain conditions—for example, microbes that might make a particular crop more tolerant of dry conditions. Promising candidates advance to greenhouse testing and eventually field testing. Indigo has announced that this year it would release its first two products, microbe-based seed coatings for two undisclosed crops. If it ends up improving crop yield, there are business implications here — not only can Indigo build itself into a real company, farmers too can improve their overall business.