Abstract

This study deals with the ingestion of fermented milk with Bifidobacterium infantis,and its effect on intestinal disorders and on the intestinal lining during antibiotherapy with amoxicillin and contamination with enteropathogenic Escherichia coli EPEC O111.B4, the latter being responsible for 45% of infant diarrhoea in Algeria. Our results showed that the growth of B. infantis was not affected either by the presence of EPEC or by the administration of Amoxicillin. Inversely, an antagonistic effect of B. infantis on EPEC was observed with inhibition rates reaching 100% whether in presence of Amoxicillin or not, with survival rates of 100% versus zero in batches where B. infantis was not ingested. An inhibiting effect on Enterobacteria was observed. After dissection of all rabbits, macroscopic and microscopic observations of histological sections of the digestive tract (small intestine and colon), showed that rabbits that received amoxicillin associated or not with contamination with EPEC suffered from  severe intestinal atrophy with degradation of intestinal tissues (lining and mucous membranes). However, a less significant impact was observed among rabbits that underwent antibiotherapy associated with contamination with EPEC but ingested fermented milk with B. infantis. Total regeneration of tissues was observed 15 days after the first dissection. On the other hand, no pathological anomaly was observed among rabbits that ingested fermented milk with B. infantis associated with contamination with EPEC or amoxicillin. These results showed that the number and the length of survival of B. infantis cells in the rabbit digestive tract during the ingestion of fermented milk withB. infantis and after ingestion ended were sufficient to enable it to exert probiotic effects. 

Key words: Bifidobacterium infantis, EPEC O111.B4, amoxicillin, diarrhoea, intestinal atrophy.