Effects of Lactobacillus pentosus in Children with Allergen-Sensitized Atopic Dermatitis.

BACKGROUND: Recent studies have shown that oral administration of probiotics may improve the immune imbalance caused by dysbiosis of the gut microbiome in atopic dermatitis (AD). This study aimed to investigate the clinical and immunological effects of Lactobacillus pentosus in children with mild to moderate AD. METHODS: Children aged 2-13 years with AD were randomized to receive either 1.0 × 1010 colony-forming units of L. pentosus or placebo, daily, for 12 weeks. The clinical severity of AD and transepidermal water loss were evaluated. Blood eosinophil counts, serum total immunoglobulin E (IgE), and cytokine levels were measured. The diversity and composition of the gut microbiota were also analyzed. RESULTS: Eighty-two children were recruited, and 41 were assigned to the probiotics intervention group. The mean scoring of atopic dermatitis (SCORAD) indices at baseline were 30.4 and 34.3 for the probiotics and placebo groups, respectively. At week 12, the mean indices were 23.6 and 23.1 for the probiotics and placebo groups, respectively. Clinical severity decreased significantly over time in both groups, with no significant difference between the two groups. In both groups, there were no significant differences in cytokine levels, microbial diversity, or the relative abundance of the gut microbiota at week 12 compared with the corresponding baseline values. The mean subjective scores of SCORAD indices after intervention for the probiotics group were significantly lower than those for the placebo group in IgE sensitized AD (P = 0.019). CONCLUSION: Our results show improved symptoms in the probiotics and placebo groups, and we could not find additional effects of L. pentosus in AD. However, the mean subjective scores of SCORAD indices for the probiotics group are significantly improved compared with those for the placebo group in allergen-sensitized AD.

Oral intervention of Lactobacillus pentosus S-PT84 attenuates the allergenic responses in a BALB/C mouse model of egg allergy.

Food protein-induced allergies are primarily aggravated due to imbalance immune responses. Earlier studies by different research groups have reported that the intervention of Lactobacillus pentosus (L. pentosus) S-PT84 can modulate T-helper (Th)1/Th2 balance through regulatory T cells and can effectively promote type 1 immunity by activating dendritic cells and natural killer cells, such biological activity makes L. pentosus S-PT84 a potential mediation in controlling food allergy. Thus, this study aimed to evaluate the effects of L. pentosus S-PT84 against egg ovalbumin (OVA)-induced allergic response in mice. BALB/c mice (n = 12/group) were sensitized with OVA (50 µg/mice) via intraperitoneal injection (IP) for four weeks and subsequently administered with three different doses of L. pentosus S-PT84 via pelleted diet. The allergenic status was assessed by clinical signs, serum histamine, mouse mast cell protease (MMCP) level, and antibody activity, cytokines level in splenocytes, and expression of T regulatory cells (T-regs) in blood. The intervention of L. pentosus S-PT84, precisely at the high dose (0.6 % L. pentosus S-PT84 in pelleted diet) group, significantly reduced the clinical allergenic symptoms and reduced the histamine and MMCP levels in serum. However, the intervention of L. pentosus S-PT84 did not affect the OVA-specific IgE, IgG concentration, but led to lower the total IgE and IgG titers, suggesting that the therapeutic effect of L. pentosus S-PT84 may be due to development of immune tolerance. Moreover, differences in the immune response were observed after L. pentosus S-PT84 intervention, as it significantly reduced the production of IL-4, IL-17, and increased the population of CD25+Foxp3+ cells. Thus, it can be concluded that the intervention of L. pentosus S-PT84 provides a potential therapeutic strategy to reduce the chicken egg OVA-induced allergic symptoms.

Understanding the roles of surface proteins in regulation of Lactobacillus pentosus HC-2 to immune response and bacterial diversity in midgut of Litopenaeus vannamei.

The interactions of microbiota in the intestines play an important role in promoting or maintaining the health of hosts. The present study aim to investigate the effects of the surface proteins of Lactobacillus pentosus HC-2 on the immune response and the bacterial composition of Litopenaeus vannamei, thus, the immune-related genes, surface condition, HC-2 numbers and the bacteria diversity in midgut were explored after shrimp feeding the normal HC-2 and 5 M -  lithium chloride (LiCl) treated HC-2 for four weeks. Obvious improvements in the intestinal surface were observed in R group than the control group and L group. qPCR analysis demonstrated that the selected immune-related genes of lysozyme, proPO, LGBP, PEN-3α, crustin, and lvLec were significantly up-regulated in group R than in group L. Meanwhile, in the challenge test, shrimp in R group received 72% relative percent survival, which was significantly higher than the L group (RPS = 9%). The bacteria composition analysis showed that the abundance of Proteobacteria were significantly higher in group R and L than in group C, and the Bacteroidetes were significantly higher in group C than in group R and L, whereas the numbers of Chloroflexi were significantly higher in group R than in group C and L. The bacterial community difference analysis revealed that the harmful bacteria such as genus of Vibrio, Tenacibaculu and Thalassobius were decreased and the beneficial bacterium as Ruegeria and Lactobacillus were increased in R group, whereas this phenomenon were not found in L group. Taken together, above results indicating that the surface proteins were indispensable for L. pentosus HC-2 adhesion and colonization in shrimp intestines to improve intestine condition, enhance immune response, competitively exclude the pathogens, and promote the beneficial bacteria growth to protect the shrimp from pathogens infection. The findings in this work will help to promote the understanding of the roles of probiotics in shrimp intestines displaying probiotic-function by regulating the intestinal bacteria.

Immunomodulation of Lactobacillus pentosus PL11 against Edwardsiella tarda infection in the head kidney cells of the Japanese eel (Anguilla japonica).

Wild and farm-raised fish can be simultaneously exposed to different types of pathogens in their habitats. Hence, it is important to study their effects, whether isolated or in combination. Therefore, the aim of this study was to evaluate the effects of Lactobacillus pentosus PL11 on the transcription of specific cytokine genes related to immune response, using Japanese eel macrophages as an in vitro model. Head kidney leukocytes were isolated from Japanese eels and cell viability was determined using an MTT reagent. In addition, the Griess reagent was used to determine the nitric oxide (NO) production while, an enzyme-linked immunosobent assay (ELISA) and a quantitative polymerase chain reaction (qPCR) were utilized to quantify the level of proinflammatory cytokines. The results of the study indicated that infection by Edwardsiella tarda alone causes a higher rate of cell death and an increase in the production of proinflammatory cytokines, such as interleukin-1ß (IL-1ß, 822.67 ± 29.48 pg mL(-1)), interleukin-6 (IL-6, 13.57 ± 0.55 pg mL(-1)), and tumor necrosis factor-α (TNF-α, 2033.67 ± 84.68 pg mL(-1)). However, co-culture with L. pentosus PL11 downregulates the production of NO and the related IL-1ß, IL-6, and TNF-α by 46%, 88.4%, 59%, and 77%, respectively. Quantification of the mRNA expression level revealed it to be consistent with the ELISA analysis. Hence, we infer that L. pentosus PL11 plays a significant role in the immunmodulation of the inflammatory responses that arise in fish owing to infection by pathogenic bacteria such as Edwardsiella tarda.