Content of short-chain fatty acids in the hindgut of rats fed processed bean (Phaseolus vulgaris) flours varying in distribution and content of indigestible carbohydrates

Abstract

Red kidney beans (Phaseolus vulgaris ) processed to differ in distribution and content of indigestible carbohydrates were used to study hindgut fermentability and production of shortchain fatty acids (SCFA). Bean flours with low or high content of resistant starch (RS), mainly raw and physically-inaccessible starch, were obtained by milling the beans before or after boiling. Flours containing retrograded starch and with a high or low content of oligosaccharides were prepared by autoclaving followed by freeze-drying with or without the boiling water. Six diets were prepared from these flours yielding a total concentration of indigestible carbohydrates of 90 or 120 g/kg (dry weight basis). The total fermentability of the indigestible carbohydrates was high with all diets (80-87 %). Raw and physically-inaccessible starch was more readily fermented than retrograded starch (97 -99 % v. 86 -95 %; P , 0 : 05). Non-starch glucans were fermented to a lesser extent than RS, but the fermentability was higher ðP , 0 : 05Þ in the case of autoclaved (50 -54 %) than boiled beans (37 -41 %). The distribution between acetic, propionic and butyric acid in the caecum was similar for all diets, with a comparatively high percentage of butyric acid (approximately 18). However, with diets containing the high amounts of RS, the butyric acid concentration was significantly higher in the distal colon than in the proximal colon (P ¼ 0 : 009 and P ¼ 0 : 047 for the high-and low-level diets respectively), whereas it remained constant, or decreased along the colon in the case of the other diets. Furthermore, the two diets richest in RS also promoted the highest percentages of butyric acid in the distal colon (24 and 17 v. 12 and 12 -16 for the high-and low-level diets respectively).Short-chain fatty acids: Red kidney beans: Indigestible carbohydrates Short-chain fatty acids (SCFA; acetic, propionic and butyric acid) formed during bacterial fermentation of carbohydrates in the colon, have been suggested to have specific physiological effects. Thus, butyric acid, the main energy substrate for the colonocytes (Roediger, 1982), may play a role in the prevention and treatment of various colonic diseases (McIntyre et al. 1993;. In colonic tumour cell lines, butyrate has been shown to inhibit growth (Whitehead et al. 1986), differentiation (Siavoshian et al. 2000) and to induce apoptosis . Further, patients with distal ulcerative colitis given rectal infusions with SCFA mixtures (Breuer et al. 1991;Vernia et al. 1995) or butyrate alone (Scheppach et al. 1992) improved, regarding symptoms and/or, histological and endoscopic scores. However, lower concentrations of SCFA or butyrate enemas had no effect on diversion colitis (Guillemot et al. 1991) or distal ulcerative colitis (Steinhart et al. 1996). Propionic acid is discussed as beneficial in relation to lipid metabolism (Venter et al. 1990;Wright et al. 1990;Todesco et al. 1991). It has thus been proposed that propionate may lower plasma cholesterol concentrations by inhibiting hepatic cholesteroge...

Formation of Short-Chain Fatty Acids, Excretion of Anthocyanins, and Microbial Diversity in Rats Fed Blackcurrants, Blackberries, and Raspberries

“…In this study, there was a correlation between the caecal tissue weight and the caecal content (correlation factor 0.69, P < 0.001), while the correlation of the caecal tissue weight and content to SCFA levels was 0.54 and 0.85, respectively ( P < 0.001). Studies in the literature are not consistent on this matter, and the increased caecal tissue weight is sometimes related to increased caecal levels of SCFAs and sometimes to the caecal content [14, 45, 46]. …”

Short‐chain fatty acid content in the hindgut of rats fed various composite foods and commercial dietary fibre fractions from similar sources

“…Similarly, we have shown earlier that butyric acid concentration increased in the distal colon of rats fed a mixed diet containing high amounts of RS from potatoes and peas (Berggren AB, Bjo È rck IME and Nyman EMGL, unpublished results) or from red kidney bean¯our. 44 The high proportion of butyric acid produced from potato powder in the distal colon is interesting, as butyrate has been suggested to have a therapeutic effect in distal ulcerative colitis. 45 Further, butyric acid might prevent colon cancer, 5,6,46 which predominantly occurs in the distal part of the colon in both humans and experimentally induced rodent cancer models.…”

Rapid determination of short-chain fatty acids in colonic contents and faeces of humans and rats by acidified water-extraction and direct-injection gas chromatography

“…SCFAs are mainly formed from colonic fermentation of indigestible carbohydrates (Henningsson et al, 2001), but small amounts of branched SCFA may also be formed from indigestible protein (Cummings and Englyst, 1987). Although acetic acid, propionic acid and nbutyric acid are thought to be the most important SCFAs formed, i-butyric acid, n-valeric acid, i-valeric acid, n-caproic acid and n-heptanoic acid can also be found in faeces, like considerable amounts of lactic acid and succinic acid (Chen et al, 2001;Ebihara et al, 1998;Mills et al, 1999).…”