Anti-Inflammatory and Gut Microbiota Modulating Effects of Probiotic Lactobacillus paracasei MSMC39-1 on Dextran Sulfate Sodium-Induced Colitis in Rats.

Probiotics have been shown to possess several properties, depending on the strain. Some probiotics have important roles in preventing infection and balancing the immune system due to the interaction between the intestinal mucosa and cells in the immune system. This study aimed to examine the properties of three probiotic strains using the tumor necrosis factor-alpha (TNF-α) inhibition test in colorectal adenocarcinoma cells (Caco-2 cells). It was revealed that the viable cells and heat-killed cells of the probiotic L. paracasei strain MSMC39-1 dramatically suppressed TNF-α secretion in Caco-2 cells. The strongest strains were then chosen to treat rats with colitis induced by dextran sulfate sodium (DSS). Viable cells of the probiotic L. paracasei strain MSMC39-1 reduced aspartate transaminase and alanine transaminase in the serum and significantly inhibited TNF-α secretion in the colon and liver tissues. Treatment with the probiotic L. paracasei strain MSMC39-1 alleviated the colon and liver histopathology in DSS-induced colitis rats. Furthermore, supplementation with probiotic L. paracasei strain MSMC39-1 increased the genus Lactobacillus and boosted the other beneficial bacteria in the gut. Thus, the probiotic L. paracasei strain MSMC39-1 exhibited an anti-inflammation effect in the colon and modulated the gut microbiota.

Microencapsulation of probiotic Lactobacillus brevis ST-69 producing GABA using alginate supplemented with nanocrystalline starch.

Microencapsulation technology can be used to improve the probiotic viability under stress condition in the human gastrointestinal tract and during storage. The purpose of this study was to evaluate the protective effect of encapsulation materials on the survival of GABA-producing probiotics using alginate containing cassava starch nanocrystals under simulated gastrointestinal conditions and shelf storage. Lactobacillus brevis ST-69, GABA-producing probiotic strain, was isolated from kimchi and encapsulated using emulsion technique. The GABA activity, encapsulation efficiency, morphology, probiotic viability were evaluated. The encapsulation efficiency using emulsion technique was 89.72%. Probiotic encapsulated in alginate-nanocrystalline starch gel capsules showed high survival rate at 94.97% of probiotic cells under simulated gastrointestinal conditions and during long-life storage at 4 °C compared to free cells. Results showed that for improving the viability of probiotics against gastrointestinal and storage conditions, complex materials with nanocrystalline starch might be a better encapsulating matrix for the preparation of gel capsules.

In vitro modulation of tumor necrosis factor α production in THP-1 cells by lactic acid bacteria isolated from healthy human infants.

The human microbiota is a source of probiotics capable of modulating the host immune system. In this study, we collected fecal samples from 100 healthy infants and isolated lactic acid bacteria which were screened for immune modulating effects on tumor necrosis factor α (TNF-α) production. Cell-free culture supernatants from 26 isolates were able to decrease TNF-α production in vitro and three of the isolates were selected as candidate probiotics (MSMC39-1, MSMC39-3, MSMC57-1). These isolates were identified using 16S ribosomal DNA sequencing as Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa respectively. All three isolates were acid tolerant and bile tolerant to pH 3.0 and 4% bile respectively. Preparations of cell-free culture supernatants were processed and tested, and revealed that cell-free culture supernatants of isolates L. paracasei MSMC39-1, L. casei MSMC39-3, and W. confusa MSMC57-1 decreased the production of TNF-α significantly and were heat resistant. Only L. paracasei MSMC39-1 supernatant was proteinase-K sensitive. The effects of viable bacteria, heat-killed bacteria, and sonicated bacteria were compared. The heat-killed preparations of isolate W. confusa MSMC57-1 decreased the production of TNF-α. Sonicated cell preparations did not significantly alter TNF-α production. For isolates L. paracasei MSMC39-1 and L. casei MSMC39-3, this suggests that a substance in the cell-free culture supernatant may be responsible for in vitro cytokine modulation.

Antimicrobial Properties of a Potential Probiotic Lactobacillus from Thai Newborn Feces.

BACKGROUND: Probiotics are increasingly used to treat infectious diarrhea and antibiotic-associated diarrhea. Many probiotic bacteria are classified in general such as Lactobacillus and are able to colonize the gastrointestinal tracts of infants. OBJECTIVE: This study was performed to detect antimicrobial substances and activity in 200 Lactobacillus isolates obtained from healthy Thai newborn feces. MATERIAL AND METHOD: Reuterin production was detected by the spot overlay technique and colorimetric assay. Antimicrobial activity was tested by using a well diffusion, agar method. RESULTS: Lactobacillus strain MSMC64-1 produced reuterin and demonstrated potent antimicrobial activity against seven pathogenic indicator strains with very strong inhibitory activities against Salmonella typhi DMST 5784 and methicillin resistant Staphylococcus aureus (MRSA) DMST 20651. There was strong inhibitory activity against methicillin resistant Staphylococcus aureus (MRSA) DMST20654, Vibrio parahaemolyticus DMST 5665 and Shigella dysenteriae DMST 15111. There was moderate to weak inhibitory activities against Vibrio cholerae DMST 2873 and Helicobacter pylori (H40). The Lactobacillus strain MSMC 64-1 showed resistance to acidic pH (pH 2, 3, 4) and tolerance to 1%, 2%, 3%, and 4% bile concentrations. Sequencing of the 16S ribosomal DNA identified the candidate's strain as Lactobacillus reuteri with 98% sequence homology. CONCLUSION: The active isolate could potentially be used as a probiotic to prevent and treat enteric infections.