Simultaneous culture of saliva and jejunal aspirate in the investigation of small bowel bacterial overgrowth.

Both saliva and jejunal aspirate were cultured from 22 patients with suspected small bowel bacterial overgrowth and from eight controls. Large numbers of organisms (greater than 10(6)/ml) were recovered from the jejunal aspirate of 16 subjects, in five of whom the same organisms were present in similar relative proportions in the saliva, suggesting contamination of the sample with saliva, while in 11 the jejunal organisms differed from those in saliva. In eight of these the jejunal flora was a typical 'faecal' flora usually associated with small bowel bacterial overgrowth but, in three, the jejunal floral was superficially similar to that of saliva. Distinct subpopulations of bacteria, typically Gram-positive non-sporing rods, were, however, evident in the jejunum of these patients, and were also recovered, in smaller numbers, from the jejunum of controls, suggesting that they form a distinct jejunal microflora. Culture of saliva in addition to jejunal aspirate may be useful in the recognition of contamination of the proximal small bowel with saliva, and in the diagnosis of small bowel bacterial overgrowth.