Prebiotic potential of Jerusalem artichoke (Helianthus tuberosus L.) in Wistar rats: effects of levels of supplementation on hindgut fermentation, intestinal morphology, blood metabolites and immune response

BACKGROUND Many studies have been conducted using purified prebiotics such as inulin or fructooligosaccharides (FOS) as nutraceuticals, but there is very little information available on the prebiotic potential of raw products rich in inulin and FOS, such as Jerusalem artichoke (JA; Helianthus tuberosus L.). The present experiment aimed to evaluate the prebiotic effects of JA tubers in rats. RESULTS Seventy‐two Wistar weanling rats divided into four groups were fed for 12 weeks on a basal diet fortified with pulverized JA tubers at 0 (control), 20, 40 and 60 g kg−1 levels. Enhanced cell‐mediated immunity in terms of skin indurations (P = 0.082) and CD4+ T‐lymphocyte population (P = 0.002) was observed in the JA‐supplemented groups compared with the control group. Blood haemoglobin (P = 0.017), glucose (P = 0.001), urea (P = 0.004) and calcium (P = 0.048) varied favourably upon inclusion of JA. An increasing trend (P = 0.059) in the length of large intestine was apparent in the JA‐fed groups. The tissue mass of caecum (P = 0.069) and colon (P = 0.003) was increased in the JA‐supplemented groups, accompanied by higher (P = 0.007) caecal crypt depth. The pH and ammonia concentrations of intestinal digesta decreased and those of lactate and total volatile fatty acids increased in the JA‐fed groups. CONCLUSION The results suggest that JA had beneficial effects on immunity, blood metabolites, intestinal morphometry and hindgut fermentation of rats. © 2014 Society of Chemical Industry