Beneficial bacteria that promote intestinal health in humans and livestock could get a boost of their own, thanks to a new method for turning certain sugars from corn and other crops into
complex carbohydrates called oligosaccharides.

According to Agricultural Research Service (ARS) chemist Greg Cote, the oligosaccharides have commercial potential as “prebiotics.” These are food or feed additives that nourish populations of
Lactobacillus, Bifidobacterium and other “probiotic” bacteria that live inside their hosts’ colons.

Besides unlocking minerals, vitamins and other nutrients from the oligosaccharides, probiotic bacteria can also make the colon less hospitable to pathogens, such as Salmonella and Escherichia
coli, that can cause illness in humans.

When fed to chicks or piglets, for example, the prebiotics could bolster the growth and activity of probiotic bacteria so they would outcompete Salmonella for space and
nutrientsâ€â€Âa potential boon later on, when the animals mature and are slaughtered
for their meat.

Cote, who’s in the ARS Bioproducts and Biocatalysis Research Unit at Peoria, Ill., codeveloped the oligosaccharides with Scott Holt, an associate professor with Western Illinois University’s
Department of Biological Sciences. They envision formulating the oligosaccharides as a prebiotic product that could be administered orally.

Their production method uses a microbial enzyme called alternansucrase to catalyze a series of biochemical reactions that convert sugars like sucrose, glucose or maltitol into different kinds
of oligosaccharides.

Depending on which were used, the resulting oligosaccharides bolstered the laboratory growth of Bifidobacterium, Lactobacillus, Bacteroides and some enterococci bacteria, but not pathogens such
as Salmonella, E. coli or Clostridium perfringens.

Cote’s research is part of the ARS unit’s broader mission to develop new, value-added uses for corn, soybeans and other Midwest farm crops.

Jan Suszkiw

www.ars.usda.gov