Impact of Probiotic SYNBIO(®) Administered by Vaginal Suppositories in Promoting Vaginal Health of Apparently Healthy Women.

The purpose of this study was to investigate whether vaginal administration of probiotic Lactobacillus results in their colonization and persistence in the vagina and whether it promotes normalization and maintenance of pH and Nugent score. A single-arm, open-label controlled towards the baseline (pre-post) study including 35 apparently healthy women was conducted. Each woman was examined three times during the study. Women were instructed to receive daily for 7 days, the probiotic suppositories SYNBIO(®) gin (Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®)). Vaginal swabs were collected during visit 1, 2, and 3 to determine the total lactobacilli count, the presence of the two administered bacteria, the measure of the pH, and the estimation of Nugent score. Evaluation of treatment tolerability was based on analysis of the type and occurrence of adverse events. The probiotic vaginal suppository was well tolerated and no side effects were reported. Intermediate Nugent score was registered in 40 % of women at visit 1 and these intermediate scores reverted to normal at day 7 (end of treatment) in 20 % of subjects. Administration of SYNBIO(®) gin contributed to a significant increase in the lactobacilli level at visit 2. Molecular typing revealed the presence of the two strains originating from SYNBIO(®) gin in 100 % of women at visit 2 and 34 % at visit 3. No significant changes were registered for pH between visits. The SYNBIO(®) gin product is safe for daily use in healthy women and it could be useful to restore and maintain a normal vaginal microbiota.

Probiotic-enriched foods and dietary supplement containing SYNBIO positively affects bowel habits in healthy adults: an assessment using standard statistical analysis and Support Vector Machines.

A randomised, double-blind, placebo-controlled, parallel group study assessed in healthy adults how daily consumption of the probiotic combination SYNBIO®, administered in probiotic-enriched foods or in a dietary supplement, affected bowel habits. Primary and secondary outcomes gave the overall assessment of bowel well-being, while a Psychological General Well-Being Index compiled by participants estimated the health-related quality of life as well as the gastrointestinal tolerance determined with the Gastrointestinal Symptom Rating Scale. Support Vector Machine models for classification problems were used to validate the total outcomes on bowel well-being. SYNBIO® consumption improved bowel habits of volunteers consuming the probiotic foods or capsules, while the same effects were not registered in the control groups. The recovery of probiotic bacteria from the faeces of a cohort of 100 subjects for each supplemented group showed the persistence of strains in the gastrointestinal tract.

Biogenic amines as freshness index of meat wrapped in a new active packaging system formulated with essential oils of Rosmarinus officinalis.

Biogenic amines (BAs) are considered as an important indicator of freshness and quality of food. In this work, a new active packaging (AP) system for meat that, incorporating essential oil of Rosmarinus officinalis at 4% (w/w), inhibits the increase of BAs and the bacteria involved into their production was developed. BAs were analyzed by a SPE-HPLC-DAD method during the storage time of meat (0-7 d, 4 °C). Results showed that, in each monitored day, Biogenic Amine Index (BAI) expressed in mg kg(-1) is lower in meat wrapped in AP with respect to that packed in polycoupled packaging (PP) (from 19% to 62%). A strong correlation was found between the inhibition of increase of putrescine, cadaverine, histamine and their bacteria producers such as Enterobacteriaceae, Pseudomonas spp. and Brocothrix thermospacta. By exploiting antimicrobial and antioxidant action of essential oil of R. officinalis, the new APs contribute to increase the shelf life of fresh meat and to preserve its important nutrients.

Antimicrobial efficacy of Achillea ligustica All. (Asteraceae) essential oils against reference and isolated oral microorganisms.

The aim of this study was to verify the effectiveness of Achillea ligustica essential oils against several oral microorganisms in comparison with a commercial essential oil-containing mouthrinse (Listerine(®)) and clove oil (containing 89% eugenol). The inhibition efficacy of A. ligustica essential oils alone and in combination with Listerine(®) was evaluated by the micro-dilution method. The most susceptible microorganisms were Bacillus cereus, Streptococcus pyogenes, and Candida albicans. The efficacy was similar to that of the clove oil. The antiseptic mouthwash Listerine(®) did not exert a strong inhibition on microbial strains tested, whereas its effectiveness increased significantly when essential oil was added. The study provides additional evidence for the in vitro inhibitory activity of A. ligustica essential oils on several pathogens, suggesting their usefulness in mouthrinse formulations as an adjunct to mechanical oral hygiene regimens. Essential oil-containing mouthrinses can be beneficial, safe components of daily oral health routines, representing an efficient and without side effect alternative to prevent and control oral infections.

Chemical composition and antimicrobial activity of the essential oils from several Hypericum taxa (Guttiferae) growing in central Italy (Appennino Umbro-Marchigiano).

The chemical composition of the essential oils of nine taxa from seven sections of Hypericum L. (Guttiferae; H. perforatum subsp. perforatum, H. perforatum subsp. veronense, H. calycinum, H. montanum, H. richeri subsp. richeri, H. hyssopifolium, H. hirsutum, H. hircinum subsp. majus, and H. tetrapterum) occurring in central Italy (Appennino Umbro-Marchigiano) was analyzed by GC/FID and GC/MS. A total of 186 compounds were identified in the different species and subspecies, accounting for 86.9-92.8% of the total oils. The major fraction of the oil was always represented by sesquiterpene hydrocarbons (30.3-77.2%), while quantitative differences occurred between the other classes of volatiles depending on the taxa considered. Chemical composition of the nine Hypericum entities with respect to the taxonomical classification was discussed. Essential oils obtained from six taxa, i.e., H. perforatum subsp. perforatum, H. perforatum subsp. veronense, H. calycinum, H. richeri subsp. richeri, H. hirsutum and H. tetrapterum, were also tested for their antimicrobial properties against five different microbial strains by the broth-microdilution method, and they were found to have significant activity (expressed as MIC) on B. subtilis, moderate activity on C. albicans and S. aureus, and weak activity on E. coli and E. faecalis, the most active being those from H. hirsutum, H. richeri subsp. richeri, and H. tetrapterum.

Probiotic properties of Lactobacillus rhamnosus and Lactobacillus paracasei isolated from human faeces.

BACKGROUND: The possibility of using microbes to maintain health, and to prevent or treat disease is a topic as old as microbiology. The research of novel probiotic strains is important in order to satisfy the increasing request of the market and to obtain functional products in which the probiotic cultures are more active and with better probiotic characteristics than those already present on the market. AIM OF THE STUDY: In this study, the probiotic potential of Lactobacillus strains isolated from Italian elderly human faeces was investigated. METHODS: The Lactobacillus strains were identified and examined for resistance to gastric acidity and bile toxicity, adhesion to HT-29 cells, antimicrobial activities, antibiotic susceptibility and plasmid profile. Survival of the strains through human intestine was examined in a 3 months human feeding trial. RESULTS: Two strains, Lactobacillus rhamnosus IMC 501 and Lactobacillus paracasei IMC 502, tolerated well low pH and bile acids. In antimicrobial activity assays, both strains showed inhibitory properties towards selected potential harmful microorganisms, particularly against Candida albicans. The two selected strains expressed high in vitro adherence to HT-29 cells increasing this characteristic when they are used in combination and they were resistant to vamcomycin, colistin sulphate, gentamicin, oxolinic acid and kanamycin. Moreover, the two strains could be recovered from stools of volunteers after the feeding trials. CONCLUSIONS: Lactobacillus rhamnosus IMC 501 and L. paracasei IMC 502 present favourable strain-specific properties for their utilisation as probiotics in functional foods and the high adhesion ability of the L. rhamnosus IMC 501 and L. paracasei IMC 502 used in combination, confirmed by both in vitro and in vivo study, indicate that the two bacterial strains could be used as health-promoting bacteria.

Evaluation of the hypocholesterolemic effect and prebiotic activity of a lentil (Lens culinaris Medik) extract.

SCOPE: The aim of our work was to produce a hydroalcoholic extract of lentils and to examine (a) the hypocholesterolemic action in an animal model, by studying the plasma cholesterol level and the concentration of bile acids in the feces; (b) the potential prebiotic effect, by conducting an in vitro culture fermentation experiment and assessing the level of SCFAs in the feces of rats. METHODS AND RESULTS: Lentil extract (LE) was obtained by extracting lentils with a solution of H2 0/EtOH (70/30 v/v) for 3 h, and the content of main nutrients was determined. After 71 days of diet-induced hypercholesterolemia in rats, LE reduced the cholesterol level of rats of 16.8% (p < 0.05) and increased the level of bile acids in the feces of rats (p < 0.01). LE revealed the same prebiotic activity of inulin and good bifidogenic activity, inasmuch as it enhanced the growth of Bifidobacterium spp. by 3 log (p < 0.05). The concentration of SCFAs in the feces of rats fed with LE increased during the time of the study. CONCLUSION: This new hydroalcoholic extract obtained from lentils was shown to possess hypocholesterolemic and prebiotic properties, and could have interesting applications in the field of nutraceuticals.

Red wine polyphenols influence carcinogenesis, intestinal microflora, oxidative damage and gene expression profiles of colonic mucosa in F344 rats.

Polyphenols from tea and other beverages such as red wine have been regarded with interest as possible chemopreventive agents against cancer. Here we report that red wine polyphenols (50 mg/kg) administered with the diet to F344 rats for 16 weeks inhibited colon carcinogenesis induced by azoxymethane (AOM, 7.4 mg/kg, total dose 74 mg/kg) or dimethylhydrazine (DMH, 30 mg/kg, total dose, 300 mg/kg). Polyphenol-treated animals had a consistently lower tumour yield compared to controls. In polyphenol-treated rats, the main bacterial strains in the faeces at sacrifice were Bacteroides, Lactobacillus and Bifidobacterium spp., whereas microorganisms predominantly identified in control-fed rats were Bacteroides, Clostridium and Propionibacterium spp. Wine polyphenols (57 mg/kg for 10 days, by gavage), administered to rats not treated with carcinogens, produced a significant decrease in the basal level of DNA oxidative damage of the colon mucosa as measured with the comet assay (average pyrimidine oxidation was reduced by 62% and purine oxidation by 57%, p<0.05). To further explore the molecular effects of wine polyphenols we used the microarray technology to study gene expression profiles: rats were treated with 50 mg/kg wine polyphenols for 14 days, mixed in the diet. Global expression analysis of 5707 genes revealed an extensive down-regulation of genes involved in a wide range of physiological functions, such as metabolism, transport, signal transduction and intercellular signalling. By analysing metabolic pathways with the GenMAPP software program we observed that two major regulatory pathways were down-regulated in the colon mucosa of polyphenols-treated rats: inflammatory response and steroid metabolism. We also found a down-regulation of many genes regulating cell surface antigens, metabolic enzymes and cellular response to oxidative stress. In conclusion, reduction of oxidative damage, modulation of colonic flora and variation in gene expression may all concur in the modulation of intestinal function and carcinogenesis by wine polyphenols.

Evaluation of the nutritional status of infants from mothers tested positive to HIV/AIDS in the health district of Dschang, Cameroon.

INTRODUCTION: Poor infant feeding practices are common in Africa, resulting in physical and intellectual developmental impairments. Good feeding practices are crucial, especially in the first year of growth. HIV/AIDS has worsened the clinical and nutritional status of both mothers and their children, exacerbating high rates of malnutrition. The aim of this study was to assess by participative approach, the nutritional status of infants from mothers tested positive to HIV in the health district of Dschang. METHODS: This is a cross sectional study with a period of recruitment of 2 years (2010-2012). Data Collection was done by the aim of a personal slip followed by training to strengthen the nutritional and hygienic capacity of targeted parents. Height and weight of infants were measured and body mass index (BMI) calculated. RESULTS: Significant difference (p ≤ 0.05) was noticed in height-for-age z-score (HAZ) of girls aged between 1 to 2 years compared to 1-year old girls as well as to boys of all ages, defining them as stunted. Furthermore, the weight-for-age z-score (WAZ) results indicate that both girls and boys of all age are in moderate state of malnutrition. The results of BMI thinness classified according to gender and age groups, indicates that most infants (68/130, 52.3%) showed grade 2 thinness predominantly in 2-years old both boys and girls. However, no participants fall within the normal category for age and sex, as well as overweight and obesity categories. CONCLUSION: Undernutrition exists among infants from mothers tested positive to HIV residing in Dschang, as most of the infants are underweight, and malnourished.

Effect of buckwheat flour and oat bran on growth and cell viability of the probiotic strains Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their combination SYNBIO®, in synbiotic fermented milk.

Fermented foods have a great significance since they provide and preserve large quantities of nutritious foods in a wide diversity of flavors, aromas and texture, which enrich the human diet. Originally fermented milks were developed as a means of preserving nutrients and are the most representatives of the category. The first aim of this study was to screen the effect of buckwheat flour and oat bran as prebiotics on the production of probiotic fiber-enriched fermented milks, by investigating the kinetics of acidification of buckwheat flour- and oat bran-supplemented milk fermented by Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their 1:1 combination named SYNBIO®. The probiotic strains viability, pH and sensory characteristics of the fermented fiber-enriched milk products, stored at 4 °C for 28 days were also monitored. The results showed that supplementation of whole milk with the tested probiotic strains and the two vegetable substrates results in a significant faster lowering of the pH. Also, the stability of L. rhamnosus IMC 501®, L. paracasei IMC 502® and SYNBIO® during storage at 4 °C for 28 days in buckwheat flour- and oat bran-supplemented samples was remarkably enhanced. The second aim of the study was to develop a new synbiotic product using the best combination of probiotics and prebiotics by promoting better growth and survival and be acceptable to the consumers with high concentration of probiotic strain. This new product was used to conduct a human feeding trial to validate the fermented milk as a carrier for transporting bacterial cells into the human gastrointestinal tract. The probiotic strains were recovered from fecal samples in 40 out of 40 volunteers fed for 4 weeks one portion per day of synbiotic fermented milk carrying about 10(9) viable cells.

Functional foods as carriers for SYNBIO®, a probiotic bacteria combination.

The popularity of functional foods continues to increase as consumers desire flavorful foods that will fulfil their health needs. Among these foods, probiotics may exert positive effects on the composition of gut microbiota and overall health. However, in order to be beneficial, the bacterial cultures have to remain live and active at the time of consumption. The aim of this study was to develop new probiotic food products, such as seasoned cheeses, salami, chocolate and ice-cream with a final probiotic concentration of approximately 109CFU/daily dose of Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® mixed 1:1 (SYNBIO®). The survival and viability of probiotics were determined during the foods shelf-life. The values of viable probiotic bacteria of all dairy and non-dairy foods were between 107 and 109CFU/g of food at the end of the shelf-life and for some of them the values were maintained even after the expiry date. Based on the results of the current study, all the dairy ("Caciotta" cheese, "Pecorino" cheese, "Büscion" Swiss cheese and "Fiordilatte" ice-cream) and non-dairy ("Ciauscolo" salami, Larded salami, Swiss small salami, milk chocolate, dark chocolate, organic jam and chocolate mousse) food products studied would be excellent vehicles to deliver the probiotic health effects because of the high viability of probiotics during the shelf-life of foods and in some cases even after their expiry date.

Pilot-scale production and viability analysis of freeze-dried probiotic bacteria using different protective agents.

The functional food industry requires an improvement of probiotic strain stability during storage, especially when they are stored at room temperature. In this study, the viability of freeze-dried Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®) using different protective agents (i.e., glycerine, mannitol, sorbitol, inulin, dextrin, Crystalean(®)) was determined and compared with semi skimmed milk (SSM) control. No significant differences were observed between the tested protectants and the control (SSM) during storage at refrigerated conditions. During storage at room temperature, only glycerine was found to stabilize viability better than other tested substances.

Chemical composition and antimicrobial activity of the essential oil from Ferula glauca L. (F. communis L. subsp. glauca) growing in Marche (central Italy).

The essential oil obtained from different parts of Ferula glauca L. (formerly considered as a subspecies of F. communis) growing in Marche (central Italy), was analyzed for the first time by GC-FID and GC-MS. The major volatiles were (E)-caryophyllene and caryophyllene oxide in leaves, alpha-pinene, myrcene and germacrene D in flowers, alpha- and beta-pinene in fruits, (E)-beta-farnesene, myristicin and elemicin in roots, respectively. The differences in composition detected with respect to F. communis, made the volatile fraction a reliable marker to distinguish between them, and confirm the botanical data at the base of their discrimination. Furthermore, the oil was assayed for its antimicrobial activity by the broth microdilution method. B. subtilis was found to be the most sensitive microorganism, with the lowest MIC values.

Composition and biological activity of essential oil of Achillea ligustica All. (Asteraceae) naturalized in central Italy: ideal candidate for anti-cariogenic formulations.

Essential oil from flowers (FL) and vegetative parts (VP) of Achillea ligustica (Asteraceae), naturalized after cultivation in central Italy, was investigated by GC-FID and GC-MS. The most abundant components were linalool, viridiflorol, beta-pinene, 1,8-cineole and terpinen-4-ol. The antioxidant assays (DPPH and ABTS radical scavenging assays, and beta-carotene bleaching test) demonstrated a moderate activity of essential oils. The antimicrobial activity was evaluated by the broth micro-dilution method on 6 microbial strains and showed to be quite strong against the cariogenic Gram-positive Streptococcus mutans, suggesting that this essential oil could be a valid candidate for anti-cariogenic formulations. Moderate cytotoxic activity was observed in assays on four tumour cell lines by MTT assay.

Antimicrobial activity of seven hypericum entities from central Italy.

Methanol-acetone extracts from aerial parts of seven entities of the genus Hypericum [H. perforatum L. subsp. perforatum, H. perforatum L. subsp. veronense (Schrank) Ces., H. montanum L., H. hyssopifolium Chaix, H. hirsutum L., H. hircinum L. subsp. majus (Aiton) N. Robson, H. tetrapterum Fr.] growing in the Appennino Umbro-Marchigiano (central Italy) were tested in vitro for their antimicrobial activity against two Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and the yeast Candida albicans, by the Kirby-Bauer agar diffusion method. The two H. perforatum subspecies were particularly active against Gram-positive and Gram-negative bacteria, supporting the use of these plants in the traditional medicine of central Italy to treat wounds, skin and infectious diseases. However significant values of inhibition were given also by H. hirsutum against S. aureus and P. aeruginosa, and by H. hyssopifolium, H. hircinum subsp. majus and H. tetrapterum against C. albicans. These results suggest that hypericin and hyperforin are the main components responsible for antimicrobial activity, but not the only ones, as other extracts, showing a low level of these compounds, possess evident activity. Isolation of pure compounds from the most active extracts is in progress.

Effects of administration of probiotic strains on GALT of larval gilthead seabream: Immunohistochemical and ultrastructural studies.

Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult seabream (Sparus aurata L.) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously during seabream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. Experimental group A received the probiotic strains already via rotifers from day 5 post-hatch (ph), whereas treatment of group B began with Artemia feeding from day 27 ph. Fish were sampled at day 28 ph (group A and control) and day 99 ph (groups A, B and control) for electron microscopy, histology and immunohistochemistry with the polyclonal antiserum ORa against homologous serum Ig and the mAb G7 specific for seabream acidophilic granulocytes. In all groups, timing and pattern of differentiation of the digestive tract did not differ. Furthermore, neither tissue damage nor manifest inflammation was provoked by probiotic administration. At day 28 ph, the developing GALT already housed mucosal leucocytes, including Ig(+) cells but no acidophilic granulocytes. No differences were seen between experimental groups. At day 99 ph, the density of Ig(+) cells (+51%) and acidophilic granulocytes (+284%) was significantly higher (p<0.05) in group A than in controls. Also group B had a higher density of Ig(+) cells (+17%) and acidophilic granulocytes (+130%) compared with controls, although less pronounced. Light and electron microscopy observations detailed the occurrence of heterogeneous populations of lymphocytes and granulocytes in the developing intestinal mucosa, and highlighted the net expansion of G7(+) acidophilic granulocytes (A +536%, B +292% vs. control) due to probiotic administration. Evidence is provided that early feeding with probiotic-supplemented diet increased the number of Ig(+) cells and acidophilic granulocytes in seabream gut and that the effects were more pronounced when administration started during gut metamorphosis. These results point to a stimulatory effect of probiotics on the gut immune system that correlates with improvement of fry survival.

Effect of fecal water on an in vitro model of colonic mucosal barrier function.

Fecal water (FW) has been shown to exert, in cultured cells, cytotoxic and genotoxic effects that have implications for colorectal cancer (CRC) risk. We have investigated a further biological activity of FW, namely, the ability to affect gap junctions in CACO2 cell monolayers as an index of mucosal barrier function, which is known to be disrupted in cancer. FW samples from healthy, free-living, European subjects that were divided into two broad age groups, adult (40+/-9.7 yr; n=53) and elderly (76+/-7.5 yr; n=55) were tested for effects on gap junction using the transepithelial resistance (TER) assay. Overall, treatment of CACO2 cells with FW samples from adults increased TER (+4%), whereas FW from elderly subjects decreased TER (-5%); the difference between the two groups was significant (P<0.05). We also measured several components of FW potentially associated with modulation of TER, namely, short-chain fatty acid (SCFA) and ammonia. SCFAs (propionic, acetic, and n-butyric) were significantly lower in the elderly population (-30%, -35%, and -21%, respectively, all P A pound 0.01). We consider that FW modulation of in vitro epithelial barrier function is a potentially useful noninvasive biomarker, but it requires further validation to establish its relationship to CRC risk.

Differences in fecal microbiota in different European study populations in relation to age, gender, and country: a cross-sectional study.

A cross-sectional study on intestinal microbiota composition was performed on 230 healthy subjects at four European locations in France, Germany, Italy, and Sweden. The study participants were assigned to two age groups: 20 to 50 years (mean age, 35 years; n = 85) and >60 years (mean age, 75 years; n = 145). A set of 14 group- and species-specific 16S rRNA-targeted oligonucleotide probes was applied to the analysis of fecal samples by fluorescence in situ hybridization coupled with flow cytometry. Marked country-age interactions were observed for the German and Italian study groups. These interactions were inverse for the predominant bacterial groups Eubacterium rectale-Clostridium coccoides and Bacteroides-Prevotella. Differences between European populations were observed for the Bifidobacterium group only. Proportions of bifidobacteria were two- to threefold higher in the Italian study population than in any other study group, and this effect was independent of age. Higher proportions of enterobacteria were found in all elderly volunteers independent of the location. Gender effects were observed for the Bacteroides-Prevotella group, with higher levels in males than in females. In summary, age-related differences in the microbiota makeup were detected but differed between the study populations from the four countries, each showing a characteristic colonization pattern.

Effects of different digestible carbohydrates on bile acid metabolism and SCFA production by human gut micro-flora grown in an in vitro semi-continuous culture.

The main source of carbon in the human large intestine comes from carbohydrates like starches and oligosaccharides which remain unchanged by gastric digestion. These polysaccharides are metabolised in the colon by saccharolytic bacteria whose composition is dependent upon the substrate availability. Among the metabolites produced, the short-chain fatty acids (SCFA) are important for colon function and to prevent diseases. In particular, butyrate affects several cellular functions (proliferation, membrane synthesis, sodium absorption), and it has been shown to be protective against colorectal cancer. In addition, faecal bacteria are responsible for the conversion of primary bile acids (BA) to secondary BA, which are considered tumor promoters. In this study we investigated the in vitro effect of different substrates (CrystaLean starch, xylo-oligosaccharides, corn starch) supplied to human faecal micro-flora, on the SCFA production, on the bowel micro-flora composition and on the primary BA conversion rate. In addition, with corn starch as substrate, we considered the effect of enriching normal human faecal micro-flora with lactobacilli and bifidobacteria, on the above reported parameters.

Fecal levels of short-chain fatty acids and bile acids as determinants of colonic mucosal cell proliferation in humans.

We studied the correlation between fecal levels of short-chain fatty acids (SCFA), bile acids (BA), and colonic mucosal proliferation in humans on a free diet. Subjects [n = 43: 27 men and 16 women; 61 +/- 7 and 59 +/- 6 (SE) yr old, respectively] were outpatients who previously underwent resection of at least two sporadic colon polyps. Mucosal proliferation was determined by [3H]thymidine incorporation in vitro in three colorectal biopsies obtained without cathartics and was expressed as labeling index (LI). BA were analyzed in feces by mass spectrometry and SCFA by gas chromatography. We found that increasing levels of BA in feces did not correlate with higher LI. On the contrary, higher levels of SCFA were significantly associated with lower LI in the colonic mucosa (P for trend = 0.02). In conclusion, in humans on a free diet, intestinal proliferation seems to be regulated by the levels of SCFA in feces and not by BA. Because a lower intestinal proliferation is associated with a decreased colon cancer risk, treatments or diets that increase colonic levels of SCFA might be beneficial for colonic mucosa.