The aim of the present work was to compare the capacity to modulate the intestinal microbiota and the production of metabolites after 14 d administration of a commercial dietary supplement and a manufactured ice cream, both containing the same quantity of inulin and the same viable counts of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis BB-12, using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model. Samples of the colonic contents were evaluated microbiologically by real-time quantitative PCR (qRT-PCR) and next-generation sequencing and chemically by the production of SCFA (acetate, propionate and butyrate) and ammonium ions ($\text{NH}_4^ + $). Statistical analyses were carried out for all the variables using the two-way ANOVA followed by the Tukey multiple comparisons test (P < 0·05) for metabolite production, qRT-PCR and the bioinformatics analysis for microbiota diversity. Dietary supplement and ice cream were able to deliver the probiotic L. acidophilus and B. animalis to the simulated colon and modulate the microbiota, increasing beneficial micro-organisms such as Bifidobacterium spp., Bacteroides spp. and Faecalibacterium spp. for dietary supplement administration, and Lactobacillus spp. for ice cream supplementation. However, the ice cream matrix was probably more favourable for the maintenance of the metabolic activity of the probiotics in the SHIME® model, due to the larger amounts of acetate, propionate, butyrate and ammonium ions obtained after 14 d of supplementation. In conclusion, both ways of probiotic supplementation could be efficient, each with its own particularities.

A total of forty weaned pigs ((Landrace×Yorkshire)×Duroc) were used to evaluate the effects of Lactobacillus acidophilus on inflammatory activity after lipopolysaccharide (LPS) challenge. Experimental treatments were as follows: (T1) control diet+saline challenge; (T2) control diet with 0·1 % L. acidophilus+saline challenge; (T3) control diet+LPS challenge; and (T4) control diet with 0·1 % L. acidophilus+LPS challenge. On d-14, piglets were challenged with saline (T1 and T2) or LPS (T3 and T4). Blood samples were obtained at 0, 2, 4, 6 and 12 h after being challenged and analysed for immune cell cytokine production and gene expression pattern. The L. acidophilus treatment increased the average daily weight gain (ADWG) and average daily feed intake (ADFI) compared with the control diet. With the control diet, the LPS challenge (T3) increased the number of immune cells and expression of TNF-α and IL-6 compared with the saline challenge (T1). Whereas with the saline challenge L. acidophilus treatment (T2) increased the number of leucocytes and CD4 compared with the control diet (T1), with the LPS challenge L. acidophilus treatment (T4) decreased the number of leucocytes, lymphocytes, CD4+ and CD8+ and expression of TNF-α and IL-6 compared with the control diet (T3). L. acidophilus treatment decreased the expression of TRL4 and NF-κB in peripheral blood mononuclear cells (PBMC) after LPS challenge, which leads to inhibition of TNF-α, IFN-γ, IL-6, IL-8 and IL1B1 and to induction of IL-4 and IL-10. We suggested that L. acidophilus improved ADWG and ADFI and protected against LPS-induced inflammatory responses by regulating TLR4 and NF-κB expression in porcine PBMC.

A total of twenty-four Yorkshire gilt pigs of 6–7 weeks of age were used in a 2×2 factorial experiment to determine the individual and combined effects of the inclusion of two dietary factors (cholesterol rich, 3 % β-cyclodextrin (BCD) and Lactobacillus acidophilus cultures) on total cholesterol and LDL-cholesterol levels in blood serum. Pigs were assigned randomly to treatment groups (n 6). Total serum cholesterol concentrations decreased after 3 weeks in all the experimental treatment groups, including diets with BCD, L. acidophilus or both. Similar trends were observed for serum LDL-cholesterol concentrations among the experimental treatments. No statistically significant differences from the control group were observed in either total serum cholesterol or LDL-cholesterol concentrations (P<0·05) for each of the individual treatment groups: BCD or L. acidophilus. However, significant differences in total serum cholesterol concentrations were observed when comparing the combined treatment group (BCD and L. acidophilus) with the control group, which consisted of a basal diet and sterile milk. The combined treatment group exhibited 17·9 % lower total serum cholesterol concentration after 3 weeks. Similar significant differences were observed when comparing the combined effect experimental group with the control group after 3 weeks. The combined treatment group exhibited 27·9 % lower serum LDL-cholesterol concentrations.

To assess the effect of Lactobacillus acidophilus (American Type Culture Collection (ATCC) 700396) on enterotoxigenic Escherichia coli (ETEC) infection, in the present study, a parallel, double-blind, placebo-controlled 4-week intervention was performed in healthy males. The subjects largely consumed their habitual diet, but had to abstain from consuming dairy foods generally high in Ca. The subjects were randomised into the L. acidophilus (dose 109 colony-forming units twice daily; n 20) or the placebo (n 19) group. After an adaptation period of 2 weeks, the subjects were orally infected with a live, but attenuated, ETEC vaccine, able to induce mild, short-lived symptoms. Before and after the challenge, the subjects recorded stool consistency, bowel habits, and frequency and severity of gastrointestinal complaints. The ETEC challenge led to a significant increase in faecal output on the 2nd day and a concomitant increase in Bristol stool scale scores. Likewise, abdominal pain, bloating, flatulence, fever, headache and nausea peaked 1 d after the oral challenge. The concentrations of faecal calprotectin and IgA peaked 2 d after and that of serum IgM peaked 9 and 15 d after the oral challenge. The concentrations of serum IgA and IgG were unaffected. The ETEC challenge led to a reduction in the number of Bacteroides–Prevotella, Bifidobacterium, Clostridium cluster XIVab and total faecal bacteria. Probiotic treatment was associated with a larger increase in Bristol stool scale scores and more fever, headache and nausea after the ETEC challenge compared with the placebo treatment. These differences were, however, small and with substantial variation within the groups. Oral application of an attenuated live ETEC vaccine provides a useful model for food-borne infections. Supplementation with L. acidophilus ATCC 700396, however, was ineffective in reducing ETEC infection symptoms in healthy men.

Conventional medical therapies for ulcerative colitis (UC) are still limited due to the adverse side effects like dose-dependent diarrhoea and insufficient potency to keep in remission for long-term periods. So, new alternatives that provide more effective and safe therapies for ulcerative colitis are constantly being sought. In the present study, probiotic LaBb Dahi was selected for investigation of its therapeutic effect on DSS-induced colitis model in mice. LaBb Dahi was prepared by co-culturing Dahi culture of Lactococci along with selected strain of Lactobacillus acidophilus LaVK2 and Bifidobacterium bifidum BbVK3 in buffalo milk. Four groups of mice (12 each) were fed for 17 d with buffalo milk (normal control), buffalo milk plus DSS (Colitis control), Dahi plus DSS, and LaBb Dahi plus DSS, respectively, with basal diet. The disease activity scores, weight loss, organ weight, colon length, myeloperoxidase (MPO) and β-glucoronidase activity was assessed, and the histopathological picture of the colon of mice was studied. All colitis control mice evidenced significant increase in MPO, β-glucoronidase activity and showed high disease activity scores along with histological damage to colonic tissue. Feeding with LaBb Dahi offered significant reduction in MPO activity, β-glucoronidase activity and improved disease activity scores. We found significant decline in length of colon, organ weight and body weight in colitis induced controls which were improved significantly by feeding LaBb Dahi. The present study suggests that LaBb Dahi can be used as a potential nutraceutical intervention to combat UC related changes and may offer effective adjunctive treatment for management of UC.

This study evaluated the effects of probiotic Dahi administration in ageing mice on macrophage and lymphocyte functions. Probiotic Dahi were prepared by co-culturing in buffalo milk (3% fat) Dahi bacteria (Lactococcus lactis ssp. cremoris NCDC-86 and Lc. lactis ssp. lactis biovar diacetylactis NCDC-60) along with Lactobacillus acidophilus LaVK2 (La-Dahi) or combined Lb. acidophilus and Bifidobacterium bifidum BbVK3 (LaBb-Dahi). Four groups of 12 mo old mice were fed for four months, with the supplements (5 g/day) of buffalo milk (3% fat), Dahi, La-Dahi and LaBb-Dahi, respectively, in addition to basal diet, and a fifth group that received no supplements served as control. The immune functions of young mice (4 mo old) were also compared with those of ageing adult mice (16 mo old). The production of nitric oxide and cytokines IL-6 and TNF-α declined and that of immunosuppressive prostaglandin E2 (PGE2) increased by stimulated peritoneal and splenic macrophages in ageing mice, compared with their young counterparts. The proliferation of stimulated splenocytes diminished and the production of IL-2 decreased and that of IL-6 and TNF-α enhanced in ageing compared with young mice. Feeding ageing mice with La-Dahi or LaBb-Dahi improved peritoneal macrophage functions stimulating nitric oxide and IL-6 and diminishing PGE2 production. Feeding La-Dahi or LaBb-Dahi also improved lymphocyte functions stimulating their proliferation and production of IL-2 in ageing mice. To conclude, the probiotic La-Dahi and LaBb-Dahi are effective in reversing age related decline in immune functions in mice.

Lactic acid bacteria can affect the maturation of immune cells and their products not only in the gut but also on the systemic immune organs such as lymph nodes and spleen. In the present work, we studied the effects of oral administration of Lactobacillus acidophilus on the immune responses of BALB/c mice bearing transplanted breast tumour. Two groups of female inbred BALB/c mice, each containing nine mice as test and control, were used. The L. acidophilus ATCC4356 strain was inoculated in DeMan–Rogosa–Sharpe broth and cultivated for 24 h at 37°C. Then, it was collected by centrifugation, and was washed and suspended in PBS. Afterwards, 0·5 ml/d of this suspension, which contained 2·7 × 108 colony forming units/ml of bacteria, was orally administered to the mice by gavage, 14 d before tumour transplantation and 30 d after that with 3-d intervals. Similar to the test mice, the control mice received an equal volume of PBS. The results showed that oral administration of L. acidophilus increased the production of IL-12 (P < 0·05) and decreased the level of transforming growth factor β (P = 0·05) in the splenocyte culture. Moreover, the growth rate of tumour in the test mice decreased (P < 0·01), and the results of delayed-type hypersensitivity assay after 48 h were risen (P < 0·05) in comparison with the controls. Results suggest that daily consumption of L. acidophilus can improve the production of immunomodulatory cytokine IL-12 in the splenocyte culture, which was stimulated by tumour antigen in BALB/c mice bearing transplanted breast tumour. But further studies are needed to find out some other possible mechanisms of this effect.

This study aimed to evaluate the effect of milk fermented with Lactobacillus acidophilus 145 and Bifidobacterium longum BB536 on plasma lipids in a sample of adult women. A double-blind, placebo controlled, cross-over study (two periods of four weeks each separated by a 1-week washout period) was performed in 34 women, aged between 18 and 65 years. Group A consumed 125 g fermented milk three times a day for the first 4 weeks while group B consumed regular yoghurt under the same conditions. (Groups A and B switched products for the second treatment period). Women taking the test product with a baseline total cholesterol above 190 mg/dl showed a significant reduction in LDL cholesterol. HDL cholesterol was also reduced by the test product. We conclude that the fermented milk may help to reduce LDL levels in hypercholesterolemic adult women.

Elevated blood cholesterol is an important risk factor associated with atherosclerosis and CHD. The search for mediators that fine tune cholesterol homeostasis has recognised probiotics as being potentially beneficial. Here, we present data describing bacterial regulation of Niemann-Pick C1-like 1 (NPC1L1), which, when weakly expressed, results in a marked reduction in intestinal absorption of cholesterol. The probiotic Lactobacillus acidophilus ATCC 4356 reduced NPC1L1 gene expression and inhibited the cellular uptake of micellar cholesterol in Caco-2 cells. Soluble effector molecules secreted by ATCC 4356 were shown to be responsible for the decrease in NPC1L1. Furthermore, ATCC 4356 mediated this effect partly through the liver X receptors (LXR). The role of NPC1L1 and the LXR in cholesterol metabolism underscores the basis for the use of probiotics, such as ATCC 4356, in managing hypercholesterolaemia.

With increasing age, a number of physiological changes take place which are reflected in immune and bowel function. These changes may relate to the commonly assumed age-related changes in intestinal microbiota; most noticeably a reduction in bifidobacteria. The current study aimed at modifying the intestinal microbiota with a potential synbiotic on selected immune and microbiota markers. Healthy elderly subjects were randomised to consume during 2 weeks either a placebo (sucrose) or a combination of lactitol and Lactobacillus acidophilus NCFM twice daily in a double-blind parallel trial. After the intervention, stool frequency was higher in the synbiotic group than in the placebo group and a significant increase in faecal L. acidophilus NCFM levels was observed in the synbiotic group, after baseline correction. In contrast to the generally held opinion, the study subjects had faecal Bifidobacterium levels that were similar to those reported in healthy young adults. These levels were, nevertheless, significantly increased by the intervention. Levels of SCFA were not changed significantly. Of the measured immune markers, PGE2 levels were different between treatments and IgA levels changed over time. These changes were modest which may relate to the fact that the volunteers were healthy. Spermidine levels changed over time which may suggest an improved mucosal integrity and intestinal motility. The results suggest that consumption of lactitol combined with L. acidophilus NCFM twice daily may improve some markers of the intestinal microbiota composition and mucosal functions.

The influence of carbonation on the evolution of lactose, galactose and glucose in fermented milks with added probiotic bacteria (Lactobacillus casei, Lactobacillus acidophilus and/or Bifidobacterium bifidum) was evaluated and related to β-galactosidase activity of starter strains. During incubation and first days of refrigeration, lactose hydrolysis resulting in the liberation of galactose and glucose occurred in CT (Streptococcus thermophilus/Lb. casei), AT (Str. thermophilus/Lb. acidophilus) and ABT fermented milks (Str. thermophilus/Lb. acidophilus/Bifid. bifidum). Levels of galactose were higher than those of glucose and could be related to the preferential consumption of glucose by actively growing bacteria. Through the incubation, lactose and monosaccharide levels were not affected by milk carbonation. However, during refrigerated storage the presence of this gas was associated with slightly lower content of lactose and higher levels of galactose and glucose in AT and ABT products but not in CT fermented milks. Through the refrigeration galactose was moderately utilised by Lb. acidophilus in AT products whereas the presence of Bifid. bifidum seems to prevent the consumption of this sugar in ABT fermented milks. Glucose remained constant, with minor variations in CT products but a continuous increase of this sugar occurred in carbonated AT and ABT fermented milks during storage. β-Galactosidase activity displayed by Str. thermophilus strains was similar at pH 6·5 (initial pH of non-carbonated samples) and pH 6·3 (initial pH of carbonated samples) whereas Lb. acidophilus LaA3 showed greater β-galactosidase activity at pH 6·3 than at higher pH values. Thus, the enhanced metabolic activity of Lb. acidophilus caused by the low initial pH of carbonated milk also promoted higher cellular β-galactosidase activity that could have released greater amounts of galactose and glucose from lactose in AT and ABT fermented milks through the refrigerated period. In CT fermented milks, similar β-galactosidase activity levels of Str. thermophilus at pH 6·5 and 6·3 together with the absence of β-galactosidase activity in Lb. casei could explain the lack of differences on glucose and galactose content between carbonated and non-carbonated samples.

The effect of a mixture of organisms (a probiotic mixture) comprising Bacillus, Lactobacillus, Streptococcus, Clostridium, Saccharomyces and Candida(107–8 colony-forming units/g rice bran of each component) on lipid metabolism was compared with that of L. acidophilus and that of S. faecalis. There were four treatment groups: rice bran (control), the mixture of organisms, L. acihphifus or S. faecds (30g/kg) were given to rats in a fat- and cholesterol-enriched diet for 4 weeks. The serum total cholesterol concentration of the group fed on the mixture of organisms was reduced by 15–33% compared with the other groups at the end of the 4week feeding period (P < 0·05). This group also had a lower hepatic cholesterol concentration (36–44%) than the two single-bacteria groups (P < 0·05). 3-Hydmxy-3-methylglutaryl-Co A reductase (NADPH; EC 1.1.1.34) activities of the mixed-organism and L. acidophifus groups were significantly lower (61–63%) than those of the other groups (P < 0·05); the activity of the S. faecalis group was also signikantly lower (42%) than that of the control group (P < 0·05). The faecal cholesterol and bile acid concentrations of the mixed-organism group increased compared with those of the L. acidophilus and S. faecalis groups (P < 0·05). The capacity of the mixed- organism cells to bind bile salt in vitro was significantly higher (approximately 50%) than that of the singlebacteria cells (P < 0·05). On the other hand, cholesterol micelle formation for the mixed-organism cells was significantly (approximately 9%) lower than that of the singlebacteria cells (P < 0·05). These results indicate that the mixture of organisms decreased the synthesis of cholesterol in the liver and increased the loss of steroids from the intestine, in rats. Thus, the mixture of organisms had a hypocholeaterolaemic role