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Immune measures and the fecal bacterial community were examined in female Biobreeding rats housed in wire bottom cages (wire) or in solid bottom cages containing hardwood chips (bedding). Housing did not affect food intake, weight gain, fecal output or fibre content, serum liver enzymes, or spleen and mesenteric lymph node immune cell populations. Bedding-housed rat feces were enriched in phylotypes aligning within the phylum Firmicutes (families Lactobacillaceae and Erysipelotrichaceae ) and had a 2-fold lower content of phylotypes aligning within the phylum Bacteroidetes . Feces from bedding-housed rats also contained significantly more acetic acid and less propionic, isobutyric, valeric and isovaleric acids than those housed on wire. Bedding-housed rats had significantly higher splenic concentrations of interleukin-4 ( P  < 0.001). These results demonstrate that bedding can indirectly influence systemic and mucosal immune measures, potentially adding additional complexities and confounding results to nutrition studies investigating the health effects of dietary fibres. [ABSTRACT FROM AUTHOR]

In order to develop approaches for reducing the carbon footprint of the swine and dairy industries, it is important first to identify the methanogenic communities that drive methane emissions from stored manure. In this study, the metabolically active methanogens in substrate-starved manure samples taken from two dairy and one swine manure storage tanks were identified using [ 13 C]-acetate and DNA stable-isotope probing (DNA-SIP). Molecular analysis of recovered genomic [ 13 C]-DNA revealed that two distinct clusters of unclassified methanogen populations affiliated with the Methanoculleus genus, and the populations affiliated with Methanoculleus chikugoensis assimilated acetate-derived carbon (acetate-C) in swine and dairy starved manure samples, respectively. Furthermore, carbon flow calculations indicated that these populations were the primary contributors to methane emissions during these anoxic SIP incubations. Comparative analysis of mcrA gene abundance (coding for a key enzyme of methanogenesis) for Methanoculleus spp. in fresh feces and a wider range of stored dairy or swine manure samples, by real-time quantitative PCR using newly designed specific primers, demonstrated that the abundance of this genus significantly increased during storage. The findings supported the involvement of these particular methanogen populations as methane emitters from swine and dairy manure storage tanks. The study revealed that the ability to assimilate acetate-C for growth in manure differed within the Methanoculleus genus. [ABSTRACT FROM AUTHOR]

Abstract: When assessing and managing a patient with optic neuritis (ON), the risk of future development of multiple sclerosis (MS) is an important issue, as this can be the first presentation of the disease. Although the presence of lesions on baseline brain MRI is the strongest predictor of MS conversion, some patients with normal imaging also develop MS. We aimed to estimate MS risk in patients with ON and a normal baseline MRI and identify individuals with higher risk of conversion. We performed a retrospective study including patients with idiopathic ON and normal baseline brain MRI who presented to our hospital over an 8year period. Of a total of 42 patients, 10 converted to MS: five during the first follow-up year, seven during the first 2years and all of the patients within the first 5years, with a 5year MS conversion rate of 23.8%. MS conversion rates were significantly higher in patients with history of previous symptoms suggestive of demyelination (p =0.002), cerebrospinal fluid oligoclonal bands unmatched in serum (p =0.004) and incomplete visual acuity recovery (⩽6/12) after 1year (p =0.002). Lower conversion rates were found in patients with optic disc edema (p =0.022). According to these results, a significant proportion of patients with idiopathic ON and a normal baseline brain MRI will develop MS, with a higher risk during the first 5years. Therefore, in the presence of factors in favor of MS conversion, close follow-up, including semestral medical consultations and yearly brain MRI, can be recommended. Early immunomodulatory treatment may be individually considered as it can delay conversion and reduce new lesion development rate. [Copyright &y& Elsevier]

Abstract: Despite the high level of effectiveness of natalizumab (NTZ) in the treatment of patients with multiple sclerosis (MS), concerns about its high direct cost and its safety have restricted its use. Our aim was to identify and quantify the clinical factors that predict an optimal response to NTZ. Patients with MS undergoing treatment with NTZ for at least 12months were classified as optimal responders if, during treatment, they sustained a reduction in their Kurtzke Expanded Disability Status Scale (EDSS) score of 1 point or more or experienced a reduction in annualised relapse rate (ARR) of more than 1. The remaining patients were classified as suboptimal responders and non-responders. Our subject pool included 48 patients. The variables associated with optimal response included: ARR in the previous year of at least 2, an age at first administration of 37.5years or less, a baseline EDSS score of 4.5 points or less, a disease duration of 9.5years or less and, in patients with secondary-progressive MS, a progressive-phase duration of 4.5years or less. The characteristics of the disease at its onset did not affect responsiveness, indicating that patients with highly active disease and low disability are the ideal candidates for NTZ treatment, regardless of previous clinical characteristics. [Copyright &y& Elsevier]

Proximal colon epithelial gene responses to diets containing increasing levels of dietary fermentable material (FM) from 2 different sources were measured to determine whether gene expression patterns were independent of the source of FM. Male Fischer 344 rats (10/group) were fed for 6 wk a control diet containing 10% (g/g) cellulose (0% FM); or a 2, 5, or 10% wheat bran (WB) diet (1 2, 5% FM); or a 2, 5, or 8% fructooligosaccharides (FOS) diet (2, 5, 8% FM). WB and FOS were substituted for cellulose to give a final 10% nondigestible material content including FM. Gene responses were relative to expression in rats fed the control diet. The gene response patterns associated with feeding ∼2% FM 15% WB and 2% FOS) were similar (∼10 gene changes ⩾ 1.6-fold; P ⩽ 0.01) and involved genes associated with transport (Scnn 1g. Mt1a), transcription (Zbtb16, Egr1), immunity (Fkbp5), a gut hormone (Retn1β), and lipid metabolism (Scd2, Insig1). These changes were also similar to those associated with 5% FM but only in rats fed the 10% WB diet. In contrast, the 5% FOS diet (∼5% FM) was associated with 68 gene expression changes ⩾1.6-fold (P ⩽ 0.01). The diet with the highest level of fermentation (8% FOS, ∼-8% FM) was associated with 132 changes ⩾1.6-fold (P ⩽ 0.01), including genes associated with transport, cellular proliferation, oncogene and tumor metastasis, the cell cycle, apoptosis, signal transduction, transcript regulation, immunity, gut hormones, and lipid metabolic processes. These results show that both the amount and source of FM determine proximal colon epithelial gene response patterns in rats. [ABSTRACT FROM AUTHOR]

A clear understanding of how diet alters gastrointestinal communities is important given the suggested link between gut community composition and a wide variety of disease pathologies. To characterize this link for commonly consumed dietary fiber sources, we investigated the change in the fecal community of rats fed diets containing 5% nonnutritive fiber (control), 3% (wt:wt) oat bran plus 2% nonnutritive fiber (OB), or 5% (w/w) wheat bran (WB) over a 28-d feeding trial using both molecular- and cultivation-based methodologies. Pooled fecal samples from Brats fed the same diet were analyzed at 4 time points. On d 28, bran-fed rats had approximately twice the total cultivable bacteria than rats fed the control diet. Over the course of feeding, the cultivable community was initially dominated by bacteroides, then by bifidobacteria, lactobacilli, enterococci, and various enterics. In contrast, molecular analysis revealed the appearance of new operational taxonomic units (phylotypes) that were both temporally and inequitably distributed throughout the fecal community. The majority of change occurred in 2 major lineages within the Firmicutes: the Clostridium coccoides group and the Clostridium leptum subgroup. The time course of change depended on the source of bran, with the majority of new phylotypes appearing by d 14 (OB) or d 28 (WB), although adaptation of the fecal community was slow and continued over the entire feeding trial. Bacteria) community richness was higher in bran-fed rats than in those fed the control diet. Change within the C. coccoides and C. leptum lineages likely reflect their high abundance within the gut bacterial community and the role of clostridia in fiber digestion. The results illustrate the limitations of relying solely on cultivation to assess bacterial changes and illustrate that community changes are complex in an ecosystem containing high numbers of interdependent and competing species of bacteria. [ABSTRACT FROM AUTHOR]

• Ca and PA concentrations in infant cereals differ widely. • High [PA]/[Zn] molar ratios of some infant cereals predict low Zn bioavailability. • PA markedly decreases Zn bioavailability in diets with ∼5 or 15 g Ca/kg diet. • PA modestly decreases Zn bioavailability in diets with ∼2 g Ca/kg diet. Complementary feeding of breastfed infants with foods high in bioavailable zinc (Zn) can help meet physiological requirements for Zn. Some infant cereals contain high concentrations of phytic acid (PA) and calcium (Ca) that may reduce absorbable Zn. This study measured PA, Zn and Ca concentrations in selected infant cereals sold in Canada and investigated the effects of dietary PA and Ca at concentrations present in infant cereals on Zn bioavailability in rats. Male Sprague-Dawley rats (36-day old) were fed a control diet containing normal Zn (29.1 mg/kg) and Ca (4.95 g/kg) or six test diets (n = 12/diet group). Test diets were low in Zn (8.91–9.74 mg/kg) and contained low (2.16–2.17 g/kg), normal (5.00–5.11 g/kg) or high (14.6–14.9 g/kg) Ca without or with added PA (8 g/kg). After 2 weeks, rats were killed and Zn status of the rats was assessed. PA, Zn and Ca concentrations in infant cereals (n = 20) differed widely. PA concentrations ranged from undetectable to 16.0 g/kg. Zn and Ca concentrations ranged from 7.0–29.1 mg/kg and 0.8–13.4 g/kg, respectively. The [PA]/[Zn] and [PA × Ca]/[Zn] molar ratios in infants cereals with detectable PA (16 of 20 cereals) ranged from 22–75 and 0.9–14.9 mol/kg, respectively, predicting low Zn bioavailability. Body weight, body composition (lean and fat mass), right femur weight and length measurements and Zn concentrations in serum and femur indicated that diets higher in Ca had a more pronounced negative effect on Zn status of rats fed a PA-supplemented diet. Addition of PA to the diet had a greater negative effect on Zn status when Ca concentration in the diet was higher. These results show that, in rats, higher concentrations of dietary Ca and PA interact to potentiate a decrease in bioavailable Zn and may suggest lower Zn bioavailability in infant cereals with higher PA and Ca concentrations. [ABSTRACT FROM AUTHOR]