Physiology& Behavior,Vol.60,No.6, pp. 1551–1556,1996 Copyright01996 ElsevierScienceInc. Printedin ttreUSA,All rightsreserved 0031-9384/96$15.00+.00 ELSEVIER PII S0031-9384(96)00312-5 Microflora Persistence on Duodenojejunal Flat or Normal Mucosa in Time After a Meal in Children M A R I C I A M P O L I N I S T E F A B I N A A L E S O R * D e o P e U n o F l V L G 1 5 F I a f M i L a S H F I R e c e i 7A u g 1 9 CIAMPOLINI,M., S. BINIAND A. ORSI. Microjlorapersistenceon duodenojejunal$ator normalmwosa in time after a meal in children. PHYSIOLBEHAV60(6) 1551–1556,1996.—Apathogenic role for high numbers of bacteria in the small intestine had been suggested previously by bacterial counts on lurninal aspirates, but these investigations were flawed by tbe sampling device “contamination” in the mouth and the changing nature of fluent intestinal content. A procedure was developed to sterilize the Watson biopsy capsule with HCI in the upper portion of the duodenum. Bacteria were counted in the mucosal homogenate of the first (diagnostic) duodenojejunal biopsy in 80 untreated celiac children, and in 46 children with irritable bowel syndrome (IBS) in a four-cell, controlled, randomized investigation. Persistence of bacteria on the mucosa for 20 h after the last meal was investigated in 62 subjects, and for 26 h after the last meal in 64 subjects. Bacteria, mainly streptococci and staphylococci, persisted at a concentration of 106per gram of mucosa 20 h after the last meal. The number of bacteria per gram of mucosa was 24 times higher in all 62 children of the 20-h fast groups than in all 64 chiMren of the 26-h fast groups (p < 0.001). The bacteria count in celiac children was 39 times higher in the 20-h fast group than in the 26-h one. This difference was significantly higher than the 11 times difference that was found on the normal mucosa between the 20- and 26-h fast IBS groups (p < 0.001), which was still significant. The number of bacteria on duodenojejunal mucosa depends on nutrient absorption and persists longer than the intermeal interval in these subjects. CopyrightO 1996ElsevierScienceInc. Digestion Intestinal absorption Intestinal bacteria Celiac disease Chronic diarrhea Weaning Health education Microflora Ingestive behavior Insulin resistance INTESTINAL flow and absorption of nutrients is rapid, and very few bacteria, if any, are cultivated in duodenojejunal aspirates of healthy children and adults examined in the fasting condition. Thus, 33 luminrd aspirates were sterile and 83 of 92 contained less than 105CFUS (colony-forming units) per ml in 9 studies in “healthy” children (4,6–8,13,23,24,43,47). Conversely, only 32 were sterile and 76 of 187 showed less than 105CFUSper rrd in 9 studies in children with chronic or persistent diarrhea (6,8,1 1,13,18,24,29,32,49). Both differences are highly signifi- cant and the high bacterial concentration, above 105CFUS per ml (including gram-positive cocci), may either affect the path- ogenesis or represent an index in the pathogenesis, or be a con- sequence of the disease. Studies on luminal fluid are flawed by possible contamination of sampling devices in the mouth and throat (30) and by the flushing out of luminal content (38). The same strains and similar bacterial density occur in simultaneous cultures of mucosa and lurninal aspirate (22,51,55). This mu- cosal flora might more directly affect disease than the hrminal kind. Microbiology counts on duodenojejunrd mucosa have been reported world-wide in only about 20 children in two investiga- tions (6,22), although persistence over time and changes with meals have not been investigated. METHODS Subjects Between 1981 and 1987, 140 children from 8 months to 16 years of age were consecutively selected for intestinal biopsy and randomized by use of a random-number table (5) into the ex- perimental and control groups at the Pediatric Gastroenterology Unit of Florence University. A definitive diagnosis of irritable bowel syndrome (IBS) or celiac disease was made in 126 of the 140 biopsied children after a 2-year follow-up and the 126 chil- dren were included in a four-cell, prospective, controlled, ran- domized investigation. At the end of the investigation, 62 chil- dren were assigned to a 20-h fast group and 64 to a 26-h fast group (Table 1). No child had intestinal symptoms in the 5 days before biopsy, or had febrile disease, or had used any drug or medication in the previous 3 weeks, or had been on a gluten-free diet in the last few years. The study was reviewed and approved 1To whom requests for reprints should be addressed. E-mail: CIAMPOLINI@CESITl .UNIFLIT 1551