PATTERN OF METABOLISM AND COMPOSITION OF THE FECAL MICROFLORA IN INFANTS 10 TO 18 MONTHS OLD FROM DAY-CARE-CENTERS

Background: From 5 months of age, infants are progressively introduced to a variety of foods which influence the equilibrium of the intestin al microflora. Methods: Thirty-five children aged 10-18 months from 8 day care centers in France were studied. Fecal specimens were examined for their biochemical and microbiological criteria. Results: Bifidoba cteria and Bacteroides belong to the predominant populations (9.7 and 8.6 log 10 cfu/g, respectively). The mean level of enterobacteria and enterococci were 8.0 and 7.8 log 10 cfu/g, respectively. Only 10% of t he infants presented a lactobacilli amount above 6 log 10 cfu/g. Most feces had similar pH values (mean 6.4), percentage of water (mean 76.4 %), and short chain fatty acid, ammonia and lactic acid concentrations (means 77, 6.7 and 2.3 mu mol/g, respectively). beta-galactosidase ha d the highest activity (106 IU/g of protein) and nitroreductase, the l owest (0.1 IU/g of protein). alpha-glucosidase and nitrate reductase s howed intermediate values of 17 and 4 IU/g of protein, respectively. W ith the exception of 4 infants, beta-glucosidase and beta-glucuronidas e values were low (4 and 2 IU/g of protein). Age and day care center w ere not significant factors for most parameters studied, except that r otavirus was related to day care center, with detection in 5 infants f rom the same center. Conclusions: Many biochemical parameters were com parable to those found in adults, with the exception of ammonia concen tration and beta-galactosidase activity. The fecal bacterial profile w as different than in adults, with more Bifidobacteria than Bacteroides and higher levels of facultative anaerobes. One infant suffering from gastroenteritis had distinctive biochemical and bacterial parameters. (C) 1997 Lippincott-Raven Publishers.