The Association of Diet, Intestinal Microbial Starch Utilizers and Butyrate‐Producers in Early Life

ABSTRACT

During the first year of life, infant diet changes from liquid to solid food. Resistant starch is one of the first complex carbohydrates available to gut microbiota. With the overall goal to gain mechanistic understanding on the development of microbial starch utilization capacity and its impact on fermentation activity, we investigated the interplay of diet, starch utilizers Ruminococcus bromii and Bifidobacterium adolescentis and the butyrate producer Anaerobutyricum hallii using samples from the longitudinal CARE cohort, and in vitro. Infants started to consume resistant starch at 4 months. While less than one quarter of the infants harboured starch utilizers at 5 months, occurrence increased until the end of year one. In vitro, R. bromii and B. adolescentis degraded resistant starch but only R. bromii released reducing sugars. B. adolescentis formed acetate and lactate. In co‐cultures, R. bromii with A. hallii produced more butyrate via reducing sugars than with lactate and acetate from B. adolescentis . At one year of age, infants that harboured both starch utilizer and A. hallii had higher faecal butyrate levels than those without these species. Our results suggest that differences in the mode of resistant starch degradation and cross‐feeding contributed to functional redundancy and affected butyrate formation.