Characterization of the anti-inflammatory Lactobacillus reuteri BM36301 and its probiotic benefits on aged mice.

BACKGROUND: The gut microbiota is playing more important roles in host immune regulation than was initially expected. Since many benefits of microbes are highly strain-specific and their mechanistic details remain largely elusive, further identification of new probiotic bacteria with immunoregulatory potentials is of great interest. RESULTS: We have screened our collection of probiotic lactic acid bacteria (LAB) for their efficacy in modulating host immune response. Some LAB are characterized by suppression of TNF-α induction when LAB culture supernatants are added to THP-1 cells, demonstrating the LAB's anti-inflammatory potential. These suppressive materials were not inactivated by heat or trypsin. On the other hand, treatment of THP-1 directly with live bacterial cells identified a group of pro-inflammatory LAB, which stimulated significant production of TNF-α. Among those, we chose the Lactobacillus reuteri BM36301 as an anti-inflammatory strain and the L. reuteri BM36304 as a pro-inflammatory strain, and further studied their in vivo effects. We supplied C57BL/6 mice with these bacteria in drinking water while feeding them a standard diet for 20 weeks. Interestingly, these L. reuteri strains evoked different consequences depending on the gender of the mice. That is, males treated with anti-inflammatory BM36301 experienced less weight gain and higher testosterone level; females treated with BM36301 maintained lower serum TNF-α as well as healthy skin with active folliculogenesis and hair growth. Furthermore, while males treated with pro-inflammatory BM36304 developed higher serum levels of TNF-α and insulin, in contrast females did not experience such effects from this bacteria strain. CONCLUSION: The L. reuteri BM36301 was selected as an anti-inflammatory strain in vitro. It helped mice maintain healthy conditions as they aged. These findings propose the L. reuteri BM36301 as a potential probiotic strain to improve various aspects of aging issues.

Effects of Nominal Differences in Cage Height and Floor Space on the Wellbeing of Rabbits.

The 8th edition of the Guide for the Care and Use of Laboratory Animals recommends a cage height of 16 in. for rabbits, compared with 14 in. in the previous edition. In contrast, the Animal Welfare Act Regulations prescribes a cage height of 14 in. for rabbits. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the effect of a 3-in. difference in cage height on the health, growth, behavior, and overall wellbeing of rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 in. of interior cage height (720 in(2) of floor space) or 18 in. of interior height (784 in(2) of floor space). The rabbits were observed during 25 periods (1 h each) over 7 wk, and various behavioral parameters were scored. In addition, rabbits were weighed weekly, and general clinical health was assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences in body weight gain or behavioral parameters were detected between groups housed in cages with different heights and amounts of floor space, nor were significant behavioral differences noted in individual rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy throughout the study. These results demonstrate that these differences in interior cage height neither benefit nor harm rabbits.

The Environmental Enrichment Committee.

Both the US Guide for the Care and Use of Laboratory Animals and the Canadian Council on Animal Care Guide to the Care and Use of Experimental Animals specify that suitable enrichment and social interaction with con-specifics should be considered when planning adequate housing for all laboratory animal species. In response to this dictum, the University of Notre Dame established an Environmental Enrichment Committee to develop, implement and assess an overall enrichment programme that encompasses all species housed at the Freimann Life Science Center. Although many enrichment strategies had been used prior to the formation of the committee, having the facility director formally authorize a committee gave the members credibility with the Principle Investigators, resources for programme development and time allotments for meetings and observations. The committee members began their assignment by defining the committee goals and responsibilities. Six categories for the enrichment strategies were established: social interaction, burrowing opportunities, perches and ramps, foraging opportunities, gnawing opportunities and food treats. A programme was developed to encompass the use of techniques within these categories with the animals that would benefit from them. Our experience is that the Environmental Enrichment Committee is an effective vehicle for the development and implementation of enrichment strategies.