Effects of Isomaltooligosaccharides Intake on Defecation and Intestinal Environment in Healthy Volunteers Toshiyuki KANEKO, Takanobu KOHMOTO, Hiroe KIKUCHI, Masao SHIOTA*, Tsuneya YATAKE*, Hisakazu IINO** and Keisuke TSUJI* * * Research and Development Center, Showa Sangyo Co., Ltd., Funabashi, Chiba 273 Technical Division, Showa Saneyo Co., Ltd., Kamisu, Ibaraki 314-01 Faculty of Home Economics, Showa Women's University, Setagaya-ku, Tokyo 154 National Institute of Health and Nutrition, Shinjuku-ku, Tokyo 162 The effects of isomaltooligosaccharides (IMO) intake at 10 g/day level on the fecal microflora and their metabolites were studied in seven healthy volunteers. The number of Bifidobacterium and Lactobacillus in feces were significantly increased, and in contrast not only the frequency of occurrence of Clostridium but also the percentage of Bacteroidaceae to the total microflora were decreased. The fecal contents of short chain fatty acids, especially acetic acid, were increased. The fecal ph value was significantly dropped, and the fecal contents of putrefactive products were also decreased. These results suggested that the IMO intake at 10 g/day level could improve the intestinal microflora and environment. Furthermore, the effects of IMO intake at 10 or 15 g/day level on defecation were studied in thirty-one healthy volunteers. The defecating frequency of the subjects, who suffered from constipation and excreted less than three times in 5 days, increased significantly in dose dependent manner with IMO intake. No malignant condition in gastrointestine was observed by IMO intake in this experimental condition. The contents of fecal acetic acid increased with IMO intake, and showed a significant correlations with the numbers of Bifidobacterium in feces, the frequency of defecation and fecal ph. These results suggested that 10 g/day level of daily IMO intake improved not only intestinal microflora and environment, but also the defecating frequency, and that fecal acetic acid played an important role in improvement of intestinal environment. (Received August 10, 1992)
Table 1. Profiles of the subjects and their intake ammount of isomaltool igosaccharides (IMO) Values of age and body weight are expressed as mean } SD.
Table 2. The effects of IMO intake on the defecating frequency and fecal weight Fig. 1. Frequency of defecation in subjects suffering from constipation
Table 3. Daily intake of energy and nutrients Values are calculated from the results of daily dietary record in the last two days of each week mean } SD of seven subjects., and expressed as
Table 4. Effects of IMO intake on counts of fecal microflora Values are expressed as mean } SD of logarithmic counts of microflora per gram feces. Numbers of subjects are six in 5 th week and seven in the other weeks. Values in parentheses are the number of subjects detected. Significantly different from the value of 1st week (*p ƒ0.05, **p ƒ0.01). Fig. 2. Compositional changes of fecal microflora by IMO intake
Table 5. Effects of IMO intake on ph, moisture and weight of feces Feces are collected in the last day of each experimental week. Values are expressed as mean } SD of six subjects in 5 th week and seven subjects in other weeks. Significantly different from the value of 1st week (** p ƒ0.05). Table 6. Effects of IMO intake on concentration of short-chain fatty acids (SCFA) and putrefactive products in feces Values are expressed as mean } SD. Subjects are six in 5 th week and seven in other weeks. a) Formic, propionic, butyric and valeric acids. b) Isobutyric and isovaleric acids. Significantly different from the value of 1st week ( õp
Table 7. Spearman's correlation coefficients among concentration of SCFA and number of microflora in feces, fecal ph and defecating frequency The number of subjects are twelve and seventeen during IMO free and intake periods, respectively. Significantly different (* p ƒ0.05, ** p ƒ0.01). Concentration of SCFA, logarithmic number of fecal bacteria per gram feces, fecal ph and frequency of defecation are employed for statistical analysis. Fig. 3. Individual changes of (I) compositional ratio of Bifidobacterium in feces (%), (II) fecal concentration of SCFA (mg/g wet feces), (III) fecal ph, and (IV) fecal concentration of putrefactive products (ƒêg/g wet feces).
Fig. 4. Relationships between fecal acetic acid and logarithmic counts of Bifidobacterium per gram feces, fecal ph or defecating frequency. 2) Hidaka, H., Eida, T., Takizawa, T., Tokunaga, T. and Tashiro, Y.: Bifidobacteria Microflora, 5, 37-50 (1986) 3) Kohmoto, T., Fukui, F., Takaku, H., Machida, Y., Arai, M. and Mitsuoka, T.: Bifidobacteria Microflora, 7, 61-69 (1988) 4) Kohmoto, T., Tsuji, K., Kaneko, T., Shiota, M., Fukui, F., Takaku, H., Nakagawa, Y., Ichikawa, T. and Kobayashi, S.: Biosci. Biotech. Biochem., 56, 937-940 (1992) 6) Kohmoto, T., Fukui, F., Takaku, H. and Mitsu-
oka, T.: Agric. Biol. Chem., 55, 2157-2159 (1991) 16) Wada, A., Bohnoshita, M., Tanaka, Y. and Hibi, K.: J. Chromatogr., 291, 111-118 (1984) 17) Yoshihara, I.: Agric. Biol. Chem., 43, 1985-1987 (1979)