Modulatory effects of Bifidobacterium longum BB536 on defecation in elderly patients receiving enteral feeding

AIM:To investigate the effects of the probiotic Bifidobacterium longum BB536 on the health management of elderly patients receiving enteral feeding.METHODS:Two double-blind,placebo-controlled trials were performed with long-term inpatients receiving enteral tube feeding at Kitakyushu Hospital Group,Fukuoka,Japan.BB536 was administered as BB536-L and BB536-H powders that contained approximately 2.5 × 10 10 and 5 × 10 10 cfu of BB536,respectively.In the first trial,83 patients(age range:67-101 years) were randomized into 2 groups that received placebo(placebo group) or BB536-H(BB536 group) powders.In the second trial,123 patients(age range:65-102years) were randomized into 3 groups,and each group received placebo(placebo group),BB536-L(BB536-L group),or BB536-H(BB536-H group) powders.Each patient received the study medication for 16 wk after 1 wk of pre-observation.Fecal samples were collected from each patient prior to and after the intervention during Trial 2.Clinical observations included body temperature,occurrence of infection,frequency of defecation,and fecal microbiota.RESULTS:No significant changes were observed in the frequency of defecation for either treatment in Trial 1.However,a significant change was noted in the BB536-L group(P = 0.0439) in Trial 2 but not in the placebo or BB536-H groups.Subgroup analyses based on the frequency of defecation for each patient during the pre-observation period for both trials revealed significant increases in bowel movements in patients with a low frequency of defecation and significant decreases in the bowel movements of patients with a high frequency of defecation during the intervention period in the BB536 groups.The combination of Trials 1 and 2 data revealed a modulatory effect of BB536 ingestion on the changes in bowel movements.Significantly increased bowel movements were observed in patients in the low frequency subgroup with significant intergroup differences(P < 0.01).Significantly decreased bowel movements were observed in patients in the high subgrou