Background: There are some evidences for the immunomodulation disorders in the response to intestinal microbiota in inflammatory bowel disease. Yogurt is a fermented milk product made with a starter culture consisting of different probiotics which could be colonized in intestine. However, the role of probiotics in the aetiopathogenesis of ulcerative colitis (UC) has not been clarified. To determine how the immune system responds to these bacteria this study was planned. Methods: Bifidobacterium lactis BB-12 (B. lactis) and Lactobacillus acidophilus LA-5 (L. acidophilus) were cultivated on MRS broth. PBMCs of 36 UC patients were separated by Ficoll-Hypaque centrifugation and co-cultured with different concentrations of UV killed bacteria in RPMI-1?640 plus 10% FCS for 48/72?h. IL-10, TGF-?, IFN-? and TNF-? were measured in supernatant of PBMCs by ELISA. Results: Both bacteria significantly augmented IL-10, TGF-?, IFN-? and TNF-? compared to control (p<0.001). The secretion levels of IL-10 and TGF-? by B. lactis- compared to L. acidophilus-stimulated PBMCs were significantly higher (p<0.05, p<0.01 respectively). The secretion levels of TNF-? and IFN-? by PBMCs after 72?h were significantly lower compared to 48?h stimulation by B. lactis (p<0.001, p<0.035 respectively). Conclusion: These data show that both probiotics may trigger the pro- and anti-inflammatory immune response of UC patients. It seems that IL-10/TGF-? uprising by B. lactis could be the reason of TNF-?/IFN-? reduction. Therefore albeit B. lactis still stimulates the effector Th cells but because of more stimulatory effect on Tregs, it could be a good potential therapeutic candidate for further investigation.

In this study, the effects of fat (0.5 %, 3.2 % and 5.0 %), inulin (0.0 and 1.0 %) and starter culture (0.0 %, 0.5 %, 1.0 % and 1.5 %) on the angiotensin converting enzyme (ACE)-inhibitory activity of probiotic yogurt containing nonviable bacteria were assessed. Proteolytic activities of bacteria were also investigated. Yogurts were prepared either using a sole yogurt commercial culture including Streptococcus thermophilus and Lactobacillus delbrueckii subs. bulgaricus or bifidobacterium animalis BB-12 and Lactobacillus acidophilus La5 in addition to yogurt culture. Relative degrees of proteolysis were found to be considerably higher in yogurt samples than UHT milk as the control. Both regular and probiotic yogurts showed considerable ACE-inhibitory activities. Results showed that degree of proteolysis was not influenced by different fat contents, while was increased by high concentration of starter culture (1.5 % w/w) and reduced by inulin (1 % w/w). ACE-inhibitory activities of yogurt were also negatively affected by the presence of inulin and high levels of fat (5 % w/w). Moreover, yogurt containing probiotic bacteria showed higher inhibitory against ACE in comparison to the yogurt prepared with non-probiotic strains.

Atopic dermatitis (AD) is an inflammatory skin disease which may be due to the imbalance between Th1-, Th2 and Treg cell-related immune responses. Evidences suggest that appropriate stimulation with probiotics may correct the skewed immune response in children with AD. The aim was to determine the effects of the yogurt culture on the secretion of Th1/Th2/Treg type cytokines by PBMCs from children with AD. was cultivated on MRS broth. The PBMCs from 20 children with AD were separated by Ficoll-Hypaque centrifugation and co-cultured with different concentrations of UV killed bacteria in RPMI-1640 plus 10% FCS for 48/72 h. The levels of IL-10, IL-4, IL-12 and IFN-γ were measured in supernatant of PBMCs by ELISA. significantly up-regulated the secretion of IL-10, IL-12 and IFN-γ, whereas decreased the secretion of IL-4 by PBMCs at both incubation times 48 h/72 h and both bacteria:PBMCs ratios 100:1/50:1, compared to control (p<0.05). There were no significant differences between incubation times 48 h and 72 h regarding the secretion levels of IL-12, IFN-γ and IL-4. However, the secretion of IL-10 by -stimulated PBMCs at incubation time 72 h and in the presence of bacteria:PBMCs ratio 100:1 was significantly higher than in incubation time 48 h and in the presence of bacteria:PBMCs ratio 50:1 (P<0.000 and P<0.00, respectively). These data show that may modulate the secretion of Th1-, Th2-Treg-related cytokines in AD patients. Therefore, the possible potential therapeutic of for treatment of AD should be consider in further investigation.

Summary Effects of different levels of fat and inulin on bacterial cell counts, degree of proteolysis and concentrations of organic acids in the yogurt containing inactivated cells of probiotic strains Bifidobacterium animalis and Lactobacillus acidophilus were investigated. Results showed that both L. acidophilus and B. animalis grew well in the yogurt samples reaching cell counts higher than 106 CFU mL−1 at the final pH of 4.5. Inulin at the concentration of 1% had no significant effects on the production of organic acids and cell counts of L. acidophilus, but promoted the growth of B. animalis with a reduction in the degree of proteolysis. Generally, different fat levels showed significant effects on the production of organic acids and nonsignificant effects on the cell counts of probiotic bacteria and degree of proteolysis. In case of lactic acid, the ratio of L‐ (+)to D‐ (−) isomer ranged from 50/50 to 80/20 in yogurt samples.

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