Effects of konjac glucomannan hydrolysates on the gut microflora of mice

Purpose - The aim of this study is to determine the effects of depolymerised mannans and specifically konjac glucomannan hydrolysates (GMH) on the colonic microflora of mice. Blood glucose and cholesterol were also measured. Design/methodology/approach - Two groups (n = 20) of 12-week old Wister mice were used for a period of 14 weeks. One group (treatment group) were fed diets containing 5 per cent konjac GMH dissolved in drinking water in addition to the control (group) standard diet. Faecal microflora, feed consumption, body weight, blood glucose and cholesterol were determined. Findings - The GMH promoted the growth of anaerobes and lactobacilli in the treatment group where this was statistically, highly significant (P < 0.001). Also, the hydrolysate was able to reduce highly significantly (P < 0.001) faecal Clostridium perfringens and Escherichia coli counts. A significant increase in average daily feed consumption (P < 0.05) and weekly body weight (P < 0.001) was found for the treatment group. The mean +/- SD (mmol/l) of blood glucose and cholesterol was lower in the treatment group. Originality/value - In addition to modulating the gut microflora, GMH seems to lower the blood glucose and cholesterol in mice. Although this needs to be verified by further studies, GMH could also be a candidate for possible treatment of subjects with high cholesterol and for diabetics.