Gut microbiota richness promotes its stability upon increased dietary fibre intake in healthy adults.

Gut microbiota richness and stability are important parameters in host-microbe symbiosis. Diet modification, notably using dietary fibres, might be a way to restore a high richness and stability in the gut microbiota. In this work, during a 6-week nutritional trial, 19 healthy adults consumed a basal diet supplemented with 10 or 40 g dietary fibre per day for 5 days, followed by 15-day washout periods. Fecal samples were analysed by a combination of 16S rRNA gene pyrosequencing, intestinal cell genotoxicity assay, metatranscriptomics sequencing approach and short-chain fatty analysis. This short-term change in the dietary fibre level did not have the same impact for all individuals but remained significant within each individual gut microbiota at genus level. Higher microbiota richness was associated with higher microbiota stability upon increased dietary fibre intake. Increasing fibre modulated the expression of numerous microbiota metabolic pathways such as glycan metabolism, with genes encoding carbohydrate-active enzymes active on fibre or host glycans. High microbial richness was also associated with high proportions of Prevotella and Coprococcus species and high levels of caproate and valerate. This study provides new insights on the role of gut microbial richness in healthy adults upon dietary changes and host microbes' interaction.

Health benefits and health claims of probiotics: bridging science and marketing.

Health claims for probiotics are evaluated by the Panel on Dietetic Products, Nutrition and Allergies of the European Food Safety Authority. Despite a substantial amount of basic and clinical research on the beneficial effects of probiotics, all of the evaluated claim applications thus far have received a negative opinion. With the restrictions on the use of clinical endpoints, validated biomarkers for gut health and immune health in relation to reduction in disease risk are needed. Clear-cut criteria for design as well as evaluation of future studies are needed. An open dialogue between basic and clinical scientists, regulatory authorities, food and nutrition industry, and consumers could bridge the gap between science and marketing of probiotics.

Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients.

A decrease in the abundance and biodiversity of intestinal bacteria within the dominant phylum Firmicutes has been observed repeatedly in Crohn disease (CD) patients. In this study, we determined the composition of the mucosa-associated microbiota of CD patients at the time of surgical resection and 6 months later using FISH analysis. We found that a reduction of a major member of Firmicutes, Faecalibacterium prausnitzii, is associated with a higher risk of postoperative recurrence of ileal CD. A lower proportion of F. prausnitzii on resected ileal Crohn mucosa also was associated with endoscopic recurrence at 6 months. To evaluate the immunomodulatory properties of F. prausnitzii we analyzed the anti-inflammatory effects of F. prausnitzii in both in vitro (cellular models) and in vivo [2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced] colitis in mice. In Caco-2 cells transfected with a reporter gene for NF-kappaB activity, F. prausnitzii had no effect on IL-1beta-induced NF-kappaB activity, whereas the supernatant abolished it. In vitro peripheral blood mononuclear cell stimulation by F. prausnitzii led to significantly lower IL-12 and IFN-gamma production levels and higher secretion of IL-10. Oral administration of either live F. prausnitzii or its supernatant markedly reduced the severity of TNBS colitis and tended to correct the dysbiosis associated with TNBS colitis, as demonstrated by real-time quantitative PCR (qPCR) analysis. F. prausnitzii exhibits anti-inflammatory effects on cellular and TNBS colitis models, partly due to secreted metabolites able to block NF-kappaB activation and IL-8 production. These results suggest that counterbalancing dysbiosis using F. prausnitzii as a probiotic is a promising strategy in CD treatment.

Estimation of pig fecal contamination in a river catchment by real-time PCR using two pig-specific Bacteroidales 16S rRNA genetic markers.

The microbiological quality of coastal or river water can be affected by fecal contamination from human or animal sources. To discriminate pig fecal pollution from other pollution, a library-independent microbial source tracking method targeting Bacteroidales host-specific 16S rRNA gene markers by real-time PCR was designed. Two pig-specific Bacteroidales markers (Pig-1-Bac and Pig-2-Bac) were designed using 16S rRNA gene Bacteroidales clone libraries from pig feces and slurry. For these two pig markers, 98 to 100% sensitivity and 100% specificity were obtained when tested by TaqMan real-time PCR. A decrease in the concentrations of Pig-1-Bac and Pig-2-Bac markers was observed throughout the slurry treatment chain. The two newly designed pig-specific Bacteroidales markers, plus the human-specific (HF183) and ruminant-specific (BacR) Bacteroidales markers, were then applied to river water samples (n = 24) representing 14 different sites from the French Daoulas River catchment (Brittany, France). Pig-1-Bac and Pig-2-Bac were quantified in 25% and 62.5%, respectively, of samples collected around pig farms, with concentrations ranging from 3.6 to 4.1 log10 copies per 100 ml of water. They were detected in water samples collected downstream from pig farms but never detected near cattle farms. HF183 was quantified in 90% of water samples collected downstream near Daoulas town, with concentrations ranging between 3.6 and 4.4 log10 copies per 100 ml of water, and BacR in all water samples collected around cattle farms, with concentrations ranging between 4.6 and 6.0 log10 copies per 100 ml of water. The results of this study highlight that pig fecal contamination was not as frequent as human or bovine fecal contamination and that fecal pollution generally came from multiple origins. The two pig-specific Bacteroidales markers can be applied to environmental water samples to detect pig fecal pollution.

Allergy therapy by intranasal administration with recombinant Lactococcus lactis Producing bovine beta-lactoglobulin.

BACKGROUND: In the last years, the use of probiotics such as lactic acid bacteria (LAB) has been proposed as an attractive alternative for the management of allergic diseases. A partial prevention from sensitization to bovine beta-lactoglobulin (BLG), one of the major cows' milk allergens, could be achieved in mice after intranasal administration with a recombinant LAB strain, Lactococcus lactis, producing BLG (LL-BLG). This study aimed to evaluate the effects of the LL-BLG strain in a therapeutic protocol. METHODS: Three groups of mice were first orally sensitized to cows' milk and then intranasally administered with either the LL-BLG strain, BLG protein alone or saline solution. Serum samples were collected to analyze BLG-specific IgE, IgG1 and IgG2a, and mice were further intranasally challenged with BLG to elicit a specific allergic reaction. RESULTS: Treatment with LL-BLG, but not with BLG alone, contributed to diminish IgG1 production in serum and bronchoalveolar lavage fluids. This was associated with decreased IL-4 production and enhanced IFN-gamma production by BLG-reactivated splenocytes, suggesting a switch from Th2- to Th1-immune response. Furthermore, we observed that administration of LL-BLG or LL locally reduced the allergic reaction induced after intranasal challenge, as evidenced by decreased release of IL-4 in bronchoalveolar lavage fluids. CONCLUSION: These preliminary results demonstrate the efficiency of the intranasal administration of LL-BLG for specific therapy against cows' milk-related allergy.

Power and limitations of the chloroplast trnL (UAA) intron for plant DNA barcoding.

DNA barcoding should provide rapid, accurate and automatable species identifications by using a standardized DNA region as a tag. Based on sequences available in GenBank and sequences produced for this study, we evaluated the resolution power of the whole chloroplast trnL (UAA) intron (254-767 bp) and of a shorter fragment of this intron (the P6 loop, 10-143 bp) amplified with highly conserved primers. The main limitation of the whole trnL intron for DNA barcoding remains its relatively low resolution (67.3% of the species from GenBank unambiguously identified). The resolution of the P6 loop is lower (19.5% identified) but remains higher than those of existing alternative systems. The resolution is much higher in specific contexts such as species originating from a single ecosystem, or commonly eaten plants. Despite the relatively low resolution, the whole trnL intron and its P6 loop have many advantages: the primers are highly conserved, and the amplification system is very robust. The P6 loop can even be amplified when using highly degraded DNA from processed food or from permafrost samples, and has the potential to be extensively used in food industry, in forensic science, in diet analyses based on feces and in ancient DNA studies.

Proteomic investigation of the adaptation of Lactococcus lactis to the mouse digestive tract.

Lactic acid bacteria are used on an industrial scale for the manufacturing of dairy products. It is now intended to develop novel applications of lactic acid bacteria that could be used as living vehicles for the targeting of antigens or therapeutics to the digestive mucosa. The aim of this study was to analyze the adaptations of Lactococcus lactis, a model lactic acid bacteria to the digestive tract and to identify functions required for colonization of the intestine. For this purpose, we combined gnotobiology with proteomics: axenic mice were colonized with a dairy L. lactis strain and the bacterial proteome was examined by 2-DE. As compared to cultures in broth, the proteome profile of bacteria grown in the intestine indicates the activation of metabolic pathways involved in various carbon sources assimilation and suggests the adoption of a mixed acids fermentative metabolism. We identified the product of the ywcC gene as essential for the colonization of the digestive tract and demonstrated that the corresponding gene product (YwcC) possesses a phosphogluconolactonase activity, suggesting an important role of the pentose phosphate pathway for the development of L. lactis in the digestive environment.

Fate and effects of Camembert cheese micro-organisms in the human colonic microbiota of healthy volunteers after regular Camembert consumption.

The objective of this study was to determine i) if Camembert cheese micro-organisms could be detected in fecal samples after regular consumption by human subjects and ii) the consequence of this consumption on global metabolic activities of the host colonic microbiota. An open human protocol was designed where 12 healthy volunteers were included: a 2-week period of fermented products exclusion followed by a 4-weeks Camembert ingestion period where 2x40 g/day of Camembert cheese was consumed. Stools were collected from the volunteers before consumption, twice during the ingestion period (2nd and 4th week) and once after a wash out period of 2 weeks. During the consumption of Camembert cheese, high levels of Lactococcus lactis and Leuconostoc mesenteroides were measured in fecal samples using real-time quantitative PCR, reaching median values of 8.2 and 7.5 Log(10) genome equivalents/g of stool. For Ln. mesenteroides, persistence was observed 15 days after the end of Camembert consumption. The survival of Geotrichum candidum was also assessed and the fecal concentration reached a median level of 7.1 Log(10) CFU/g in stools. Except a decreasing trend of the nitrate reductase activity, no significant modification was shown in the metabolic activities during this study.

Probiotic and prebiotic influence beyond the intestinal tract.

Probiotics and prebiotics have long been appreciated for their positive influences on gut health. Research on the mechanisms and effects of these agents shows that their impact reaches beyond the intestine. Effects on the microecology and pathology of the oral cavity, stomach, and vaginal tract have been observed. Likely mediated through immune influences, systemic effects such as reduced severity of colds or other respiratory conditions, impact on allergy incidence and symptoms, and reduced absences from work or daycare have also been noted. These observations, among others, suggest a broader spectrum of influence than commonly considered for these unique substances.

Consumption of Camembert cheese stimulates commensal enterococci in healthy human intestinal microbiota.

Enterococci are natural inhabitants of the human gastrointestinal tract and the main Gram-positive and facultative anaerobic cocci recovered in human faeces. They are also present in a variety of fermented dairy and meat products, and some rare isolates are responsible for severe infections such as endocarditis and meningitis. The aim of the present study was to evaluate the effect of Camembert cheese consumption by healthy human volunteers on the faecal enterococcal population. A highly specific real-time quantitative PCR approach was designed and used to type enterococcal species in human faeces. Two species were found, Enterococcus faecalis and Enterococcus faecium, and only the Enterococcus faecalis population was significantly enhanced after Camembert cheese consumption, whereas Escherichia coli population and the dominant microbiota remained unaffected throughout the trial.

Efficient production and secretion of bovine beta-lactoglobulin by Lactobacillus casei.

BACKGROUND: Lactic acid bacteria (LAB) are attractive tools to deliver therapeutic molecules at the mucosal level. The model LAB Lactococcus lactis has been intensively used to produce and deliver such heterologous proteins. However, compared to recombinant lactococci, lactobacilli offer some advantages such as better survival in the digestive tract and immunomodulatory properties. Here, we compared different strategies to optimize the production of bovine beta-lactoglobulin (BLG), a major cow's milk allergen, in the probiotic strain Lactobacillus casei BL23. RESULTS: Using a nisin-inducible plasmid system, we first showed that L. casei BL23 strain could efficiently secrete a reporter protein, the staphylococcal nuclease (Nuc), with the lactococcal signal peptide SPUsp45 fused to its N-terminus. The fusion of SPUsp45 failed to drive BLG secretion but led to a 10-fold increase of intracellular BLG production. Secretion was significantly improved when the synthetic propeptide LEISSTCDA (hereafter called LEISS) was added to the N-terminus of the mature moiety of BLG. Secretion rate of LEISS-BLG was 6-fold higher than that of BLG alone while intracellular production reached then about 1 mg/L of culture. The highest yield of secretion was obtained by using Nuc as carrier protein. Insertion of Nuc between LEISS and BLG resulted in a 20-fold increase in BLG secretion, up to 27 microg/L of culture. Furthermore, the lactococcal nisRK regulatory genes were integrated into the BL23 chromosome. The nisRK insertion allowed a decrease of BLG synthesis in uninduced cultures while BLG production increased by 50% after nisin induction. Moreover, modification of the induction protocol led to increase the proportion of soluble BLG to around 74% of the total BLG production. CONCLUSION: BLG production and secretion in L. casei were significantly improved by fusions to a propeptide enhancer and a carrier protein. The resulting recombinant strains will be further tested for their ability to modulate the immune response against BLG via mucosal delivery in a cow's milk allergy model in mice.

Anti-inflammatory effects of Lactobacillus casei BL23 producing or not a manganese-dependant catalase on DSS-induced colitis in mice.

BACKGROUND: Human immune cells generate large amounts of reactive oxygen species (ROS) throughout the respiratory burst that occurs during inflammation. In inflammatory bowel diseases, a sustained and abnormal activation of the immune system results in oxidative stress in the digestive tract and in a loss of intestinal homeostasis. We previously showed that the heterologous production of the Lactobacillus plantarum ATCC14431 manganese-dependant catalase (MnKat) in Lb. casei BL23 successfully enhances its survival when exposed to oxidative stress. In this study, we evaluated the preventive effects of this antioxidative Lb. casei strain in a murine model of dextran sodium sulfate (DSS)-induced moderate colitis. RESULTS: Either Lb. casei BL23 MnKat- or MnKat+ was administered daily to mice treated with DSS for 10 days. In contrast to control mice treated with PBS for which DSS induced bleeding diarrhea and mucosal lesions, mice treated with both Lb. casei strains presented a significant (p < 0.05) reduction of caecal and colonic inflammatory scores. CONCLUSION: No contribution of MnKat to the protective effect from epithelial damage has been observed in the tested conditions. In contrast, these results confirm the high interest of Lb. casei as an anti-inflammatory probiotic strain.

Clostridium difficile and Clostridium perfringens species detected in infant faecal microbiota using 16S rRNA targeted probes.

Clostridium perfringens and Clostridium difficile are pathogenic clostridia potentially associated with gastrointestinal infections and allergy in infants. To enable the molecular detection and quantification of these species in the infant gut, two 16S rRNA oligonucleotide probes were developed: Cdif198 for C. difficile and Cperf191 for C. perfringens. We defined the probes in silico using the RDP sequence database. The probes were then validated using FISH combined with flow cytometry and a collection of target and non-target strains, and faecal samples inoculated with dilutions of C. difficile and C. perfringens strains. These new probes were used to assess the composition of the intestinal microbiota of 33 infants of 1.5 to 18.5 months of age, associated with a panel of 8 probes targeting the predominant faecal bacterial groups of humans. The probes designed allowed detection and quantification of the relative proportions of C. difficile (0.5+/-1.0%) and C. perfringens (2.1+/-2.3%) in the microbiota of infants.

Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus survive gastrointestinal transit of healthy volunteers consuming yogurt.

To date, there is significant controversy as to the survival of yogurt bacteria (namely, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) after passage through the human gastrointestinal tract. Survival of both bacterial species in human feces was investigated by culture on selective media. Out of 39 samples recovered from 13 healthy subjects over a 12-day period of fresh yogurt intake, 32 and 37 samples contained viable S. thermophilus (median value of 6.3 x 10(4) CFU g(-1) of feces) and L. delbrueckii (median value of 7.2 x 10(4)CFU g(-1) of feces), respectively. The results of the present study indicate that substantial numbers of yogurt bacteria can survive human gastrointestinal transit.

Cell-surface display of E7 antigen from human papillomavirus type-16 in Lactococcus lactis and in Lactobacillus plantarum using a new cell-wall anchor from lactobacilli.

The human papillomavirus type-16 (HPV-16) E7 protein is considered a major viral oncoprotein involved in cervical cancer (CxCa) and a potential candidate for the development of a vaccine against this neoplasia. Here, two lactic acid bacteria (the model one Lactococcus lactis and a probiotic one Lactobacillus plantarum) were engineered to deliver an E7 mutant protein (E7mm), which has a reduced transforming activity and consequently, could fit better to therapeutic use in humans than the native form of E7. An efficient cell-surface display of E7mm was obtained in L. lactis using an expression cassette encoding a precursor composed of (i) the signal peptide and the first 15 amino acids of the mature part of the lactococcal Usp45 protein; (ii) E7mm and (iii) the cell-wall anchor of the Streptococcus pyogenes M6 protein (CWA(M6)). This hybrid precursor was produced but not cell-wall anchored in Lb. plantarum. We thus replaced CWA(M6) by the cell-wall anchor of a Lb. plantarum protein which allows an efficient cell-wall anchoring of E7mm in this bacterium. The E7mm production and cell-surface display in both L. lactis and a probiotic bacterium, Lb. plantarum, represent one more step towards the development of a safe and effective treatment against CxCa.

Controlled intra- or extracellular production of staphylococcal nuclease and ovine omega interferon in Lactococcus lactis.

A system for controlled targeting of heterologous protein was developed in the food-grade bacterium Lactococcus lactis. It is composed of the L. lactis strain NZ9000 and of two broad host range expression vectors pCYT:Nuc and pSEC:Nuc for, respectively, cytoplasmic and secreted staphylococcal nuclease (Nuc) nisin-inducible production. The level of intracellular production of Nuc measured with pCYT:Nuc (3 mg x l(-1)) is significantly lower than the one obtained with pSEC:Nuc ( approximately 20 mg x l(-1)). The secretion efficiency (SE) of Nuc is estimated to be approximately 70%, corresponding to approximately 15 mg of secreted Nuc x l(-1). Furthermore, we established that Nuc production continued in L. lactis 10 h after a 1-h nisin-pulse induction. This system was then used for intra- and extracellular production of a protein of therapeutical interest in L. lactis, the ovine interferon-omega (IFN-omega). The SE and the quantity of secreted active IFN-omega were evaluated respectively to be approximately 70% and approximately 1 mg x l(-1) ( approximately two-fold higher than the cytoplasmic form).

Delayed bacterial colonization of the gut alters the host immune response to oral sensitization against cow's milk proteins.

SCOPE: Cow's milk allergy is the most prevalent food allergy in infants whose immune system development is critically stimulated during postnatal gut colonization by commensal bacteria. Allergenic potential of cow's milk ß-lactoglobulin (BLG) and caseins (CAS) was investigated in germ-free (GF) BALB/c mice and in GF mice conventionalized (CVd) at 6 weeks of age. METHODS AND RESULTS: Oral sensitization to cow's milk in the presence of cholera toxin led to higher BLG-specific IgE, IgG1, and IgG2a responses in GF mice than in conventional (CV) mice. No significant difference was observed for CAS-specific IgE responses although IgG1 responses to αS1- and κ-caseins were higher in GF mice than in CV mice. CVd mice, orally inoculated with fecal preparations from CV mice, also displayed biased antibody responses compared to CV mice. Secretion of Th2 cytokines by BLG- and CAS-reactivated splenocytes of CVd mice was similar to that of GF mice whereas cytokine production by reactivated cells from mesenteric lymph nodes of CVd mice was equivalent to that of CV mice. CONCLUSION: Oral sensitization to BLG and CAS was differentially affected by the absence of gut microbiota and delayed bacterial colonization altered persistently the host immune response to oral sensitization against food antigens.

Allergenic and immunogenic potential of cow's milk ß-lactoglobulin and caseins evidenced without adjuvant in germ-free mice.

SCOPE: In most animal models of allergy, the development of an IgE response requires the use of an adjuvant. Germ-free (GF) mice exhibit Th2-polarized antibody responses combined with defective immunosuppressive mechanisms. The sensitizing potential of milk proteins was investigated in GF mice in the absence of adjuvant. METHODS AND RESULTS: ß-lactoglobulin (BLG) and whole casein (CAS) allergenicity was evaluated by means of intraperitoneal injections without adjuvant. Injections of BLG induced significant IgE and IgG1 responses in GF mice, while CAS injections provoked the production of IgG1 toward κ- and αS1-caseins. No significant antibody response was evidenced in conventional (CV) mice. After in vitro BLG-reactivation, IL-4, IL-5, IL-13 and IFN-γ productions by splenocytes were higher in GF mice than in CV mice. Heat-treatment decreased BLG allergenicity as indicated by the absence of IgE production in GF mice. However, heat-treatment increased protein immunogenicity and led to the production of anti-BLG and anti-κ-casein IgG1 in both GF and CV mice. This correlated with enhanced productions of IL-4, IL-5 and IL-13 in BLG-reactivated splenocytes from CV mice. CONCLUSION: Gut colonization by commensal bacteria appeared then to significantly reduce the susceptibility of mice toward the intrinsic allergenic and immunogenic potential of milk proteins.

Microbial dysbiosis in colorectal cancer (CRC) patients.

UNLABELLED: The composition of the human intestinal microbiota is linked to health status. The aim was to analyze the microbiota of normal and colon cancer patients in order to establish cancer-related dysbiosis. PATIENTS AND METHODS: Stool bacterial DNA was extracted prior to colonoscopy from 179 patients: 60 with colorectal cancer, and 119 with normal colonoscopy. Bacterial genes obtained by pyrosequencing of 12 stool samples (6 Normal and 6 Cancer) were subjected to a validated Principal Component Analysis (PCA) test. The dominant and subdominant bacterial population (C. leptum, C. coccoides, Bacteroides/Prevotella, Lactobacillus/Leuconostoc/Pediococcus groups, Bifidobacterium genus, and E. coli, and Faecalibacterium prausnitzii species) were quantified in all individuals using qPCR and specific IL17 producer cells in the intestinal mucosa were characterized using immunohistochemistry. FINDINGS: Pyrosequencing (Minimal sequence 200 nucleotide reads) revealed 80% of all sequences could be assigned to a total of 819 taxa based on default parameter of Classifier software. The phylogenetic core in Cancer individuals was different from that in Normal individuals according to the PCA analysis, with trends towards differences in the dominant and subdominant families of bacteria. Consequently, All-bacteria [log(10) (bacteria/g of stool)] in Normal, and Cancer individuals were similar [11.88±0.35, and 11.80±0.56, respectively, (P = 0.16)], according to qPCR values whereas among all dominant and subdominant species only those of Bacteroides/Prevotella were higher (All bacteria-specific bacterium; P = 0.009) in Cancer (-1.04±0.55) than in Normal (-1.40±0.83) individuals. IL17 immunoreactive cells were significantly expressed more in the normal mucosa of cancer patients than in those with normal colonoscopy. CONCLUSION: This is the first large series to demonstrate a composition change in the microbiota of colon cancer patients with possible impact on mucosal immune response. These data open new filed for mass screening and pathophysiology investigations.

Intragastric administration of a superoxide dismutase-producing recombinant Lactobacillus casei BL23 strain attenuates DSS colitis in mice.

Human immune cells release large amounts of reactive oxygen species (ROS) such as superoxide radical and hydrogen peroxide via respiratory burst. In inflammatory bowel diseases, a sustained and abnormal activation of the immune response results in oxidative stress of the digestive tract and in a loss of intestinal homeostasis. We previously reported that heterologous production of the Lactobacillus plantarum manganese catalase (MnKat) enhances the survival of Lb. casei BL23 when exposed to oxidative stress. Anti-inflammatory effects were observed after Lb. casei BL23 oral administrations in moderate murine dextran sodium sulfate (DSS)-induced colitis, without added effects of the MnKat production. Here, we evaluated the protective effects obtained by an improved antioxidative strategy. The Lactococcus lactis sodA gene was expressed in Lb. casei BL23 which acquired an efficient manganese superoxide dismutase (MnSOD) activity. The effects of Lb. casei MnSOD alone or in combination with Lb. casei MnKat were compared first in eukaryotic cell PMA-induced oxidative stress model and then in severe murine DSS-induced colitis. Based on ROS production assays as well as colonic histological scores, a significant reduction of both oxidative stress and inflammation was observed with Lb. casei MnSOD either alone or in combination with Lb. casei MnKat. No added effect of the presence of Lb. casei MnKat was observed. These results suggest that Lb. casei BL23 MnSOD could have anti-inflammatory effects on gut inflammation.