Paula Summanen

Some cases of late-onset (regressive) autism may involve abnormal flora because oral vancomycin, which is poorly absorbed, may lead to significant improvement in these children. Fecal flora of children with regressive autism was compared with that of control children, and clostridial counts were higher. The number of clostridial species found in the stools of children with autism was greater than in the stools of control children. Children with autism had 9 species of Clostridium not found in controls, whereas controls yielded only 3 species not found in children with autism. In all, there were 25 different clostridial species found. In gastric and duodenal specimens, the most striking finding was total absence of non-spore-forming anaerobes and microaerophilic bacteria from control children and significant numbers of such bacteria from children with autism. These studies demonstrate significant alterations in the upper and lower intestinal flora of children with late-onset autism and may provide insights into the nature of this disorder.

This study was conducted to determine the tolerance and effects of the prebiotic xylooligosaccharide (XOS) on the composition of human colonic microbiota, pH and short chain fatty acids (SCFA) in order to determine whether significant changes in the microbiota would be achievable without side effects. Healthy adult subjects (n = 32) were recruited in a double-blind, randomized, placebo-controlled study. Subjects received 1.4 g XOS, 2.8 g XOS or placebo in daily doses. The study consisted of a 2 week run-in, an 8 week intervention, and a 2 week washout phase. Stool samples were collected at baseline, after 4 and 8 weeks of intervention and 2 weeks after cessation of intervention. Samples were subjected to culture, pyrosequencing of community DNA, pH and SCFA analyses. Tolerance was evaluated by daily symptom charts. XOS was tolerated without significant gastrointestinal side effects. Bifidobacterium counts increased in both XOS groups compared to the placebo subjects, the 2.8 g per day group showed significantly greater increases than the 1.4 g per day group. Total anaerobic counts and Bacteroides fragilis group counts were significantly higher in the 2.8 g per day XOS group. There were no significant differences in the counts of Lactobacillus, Enterobacteriaceae and Clostridium between the three groups. XOS intervention had no significant effect on stool pH, SCFA or lactic acid. Pyrosequencing showed no notable shifts in bacterial diversity. XOS supplementation may be beneficial to gastrointestinal microbiota and 2.8 g per day may be more effective than 1.4 g per day. The low dose required and lack of gastrointestinal side effects makes the use of XOS as a food supplement feasible.

By using optimum sampling, transport, and culture techniques in patients with gangrenous or perforated appendicitis, we recovered than has previously been reported. Thirty patients older than 12 years with histologically documented gangrenous or perforated appendicitis had peritoneal fluid, appendiceal tissue, and abscess contents (if present) cultured. Appendiceal tissue was obtained so as to exclude the lumen. A total of 223 anaerobes and 82 aerobic or faculatative bacteria were recovered, an average of 10.2 different organisms per specimen. Twenty-one different genera and more than 40 species were encountered. Bacteroides fragilis group and Escherichia coli were isolated from almost all specimens. Within the B. fragilis group, eight species were represented. Other frequent isolates included Peptostreptococcus (80%), Pseudomonas (40% [P. aeruginosa, 23.3%, other Pseudomonas spp., 16.7%]), B. splanchnicus (40%), B. intermedius (36.7%), and Lactobacillus (36.7%). Interestingly a previously undescribed fastidious gram-negative anaerobic bacillus was isolated from nearly one half of all patients. This organism was found to have low DNA homology (by dot blot) with the known organisms most closely resembling it.