Levelling up tempeh: Enhancing the antidiarrheal potential of fermented soy products with bacterial exopolysaccharide

Enterotoxigenic Escherichia coli (ETEC) can cause diarrhea in mammals through adhesion to the intestinal surface. The inhibition of this adhesion can help mitigate the incidence of ETEC-mediated diarrhea. Tempeh, a food product made from soybean by fungal fermentation, is reported to have anti-adhesion bioactivity against ETEC. Exopolysaccharides (EPS) secreted by lactic acid bacteria (LAB) also have anti-adhesion bioactivity against ETEC. This opens up the possibility to improve the anti-adhesion potential of tempeh through the in situ presence of LAB-derived EPS.
In this PhD research, EPS-producing LAB strains were isolated from tempeh-related sources to be re-introduced in tempeh production. Through this strategy, we developed tempeh products with stronger anti-adhesion bioactivity compared to tempeh without LAB supplementation. We also demonstrated that such stronger anti-adhesion bioactivity was due to the presence of EPS in the tempeh. In conclusion, supplementation of fermented food with EPS-producing LAB is a feasible strategy to develop functional food with antidiarrheal potential.