Different analysis strategies of 16S rRNA gene data from rodent studies generate contrasting views of gut bacterial communities associated with diet, health and obesity

Background One of the main functions of diet is to nurture the gut microbiota and this relationship affects the health of the host. However, different analysis strategies can generate different views on the relative abundance of each microbial taxon, which can affect our conclusions about the significance of diet to gut health in lean and obese subjects. Here we explored the impact of using different analysis strategies to study the gut microbiota in a context of diet, health and obesity. Methods Over 15 million 16S rRNA gene sequences from published studies involving dietary interventions in obese laboratory rodents were analyzed. Three strategies were used to assign the 16S sequences to Operational Taxonomic Units (OTUs) based on the GreenGenes reference OTU sequence files clustered at 97% and 99% similarity. Results Different strategies to select OTUs influenced the relative abundance of all bacterial taxa, but the magnitude of this phenomenon showed a strong study effect. Different taxa showed up to 20% difference in relative abundance within the same study, depending on the analysis strategy. Very few OTUs were shared among the samples. ANOSIM test on unweighted UniFrac distances showed that study, sequencing technique, animal model, and dietary treatment (in that order) were the most important factors explaining the differences in bacterial communities. Except for obesity status, the contribution of diet and other factors to explain the variability in bacterial communities was lower when using weighted UniFrac distances. Predicted functional profile and high-level phenotypes of the microbiota showed that each study was associated with unique features and patterns. Conclusions The results confirm previous findings showing a strong study effect on gut microbial composition and raise concerns about the impact of analysis strategies on the membership and composition of the gut microbiota. This study may be helpful to guide future research aiming to investigate the relationship between diet, health, and the gut microbiota

Insoluble chitosan complex as a potential adsorbent for aflatoxin B1 in poultry feed

As a class of secondary metabolites or toxins produced by fungi, aflatoxins can poison humans and animals; among them, aflatoxin B1 (AFB1) is the most dangerous one owing to its carcinogenic and mutagenic properties that increase risks for hepatocellular carcinoma in humans; hence, adsorbents such as smectites are commonly included in poultry feed to mitigate their effects. In this study, chitosan was crosslinked with sodium dodecyl sulfate (SDS) to form an insoluble polymer complex that is stable at the relevant physiological pH levels. The characterization via Fourier transforms infrared spectroscopy revealed the interaction between the sulfate groups of the SDS and the amine group of chitosan (1,016 and 819 cm−1); this result was further confirmed by the X-ray diffraction patterns with a change in the crystalline structure of the chitosan-insoluble complex (2θ = 4.76°, 7°, and 22°). The morphology of the chitosan-insoluble complex obtained using a field emission scanning electron microscope (FE-SEM) revealed that particles were slightly porous. After characterization, the performance of the chemically modified polymer complex was evaluated as an adsorbent for AFB1 and compared with those of the unmodified chitosan, soluble chitosan complex, and commercial montmorillonite clay binder. In addition, the polymer complex was investigated as an adsorbent in an in vitro model for the poultry gastrointestinal system. Sequestration of AFB1 by a chemically modified polymer complex was 93.4%, equivalent to that of commercial montmorillonite clay (99.5%). However, these treatments also sequestered microminerals, particularly selenium and iron. This pH-stable, high-capacity adsorbent could be used in poultry feed to reduce the uptake of AFB1

Evaluación del aumento en peso de cervatos cola blanca alimentados con diferentes fórmulas lácteas

El estudio se desarrolló en el Centro de Mejoramiento Genético del Venado Cola Blanca del Centro de Producción Agropecuaria UANL, en el que se evaluaron los pesos al nacimiento y el crecimiento de cervatos de venado, mediante el registro de medidas corporales y de peso durante el periodo de lactancia. Para ello se formaron tres grupos: el primero se alimentó con el sustituto de leche Kitzenmilch®; el segundo con Lactoplex® y el tercero con leche de cabra, a partir de una rutina de alimentación predeterminada. Se realizaron mediciones corporales de largo total, circunferencia de tórax, altura a la cruz, entre otras, las cuales se correlacionaron con el peso y la edad. El promedio de peso al destete fue de 17.22 ± 3.69 kg para todos los grupos, con diferencias significativas entre el conjunto alimentado con leche de cabra = 21.21 ± 1.98 kg, con respecto a los que ingirieron Lactoplex® y Kitzenmilch® (P ≤ 0.05). Además, se determinaron diferencias significativas en los alimentados con Lactoplex®, 16.73 ± 1.56 kg y Kitzenmilch®, 13.88 ± 2.68 kg (P ≤ 0.05); no así entre hembras y machos (P ≥ 0.05). Se concluye que los cervatos que consumieron leche de cabra tuvieron el mayor crecimiento, con diferencias significativas en relación con los otros grupos de crianza

Mexican oregano essential oils given in drinking water on performance, carcass traits, and meat quality of broilers

The objective of this study was to evaluate the effects of 2 Mexican oregano essential oils (MOO), from Poliomintha longiflora Gray (PLG) and Lippia berlandieri Schauer (LBS), in drinking water (DWt) on the performance, slaughter variables, and meat quality of broilers over a 40 D period of growth. A total of 180 non-sexed Ross-308 broilers (1-day-old) were randomly assigned to 3 treatments with 6 replications each (10 birds per replicate): CON = DWt control (without MOO); PLG = DWt + 400 mg/L of PLG; and LBS = DWt + 400 mg/L of LBS. The CON, PLG, and LBS broilers body weights were similar (P > 0.05) at all times. Feed intake (FI) was different by treatment (P 0.05), although WG for CON was slightly higher. In CON broilers, slaughter weight was highest (P < 0.05), but thigh yield was lowest (P < 0.05). The CON and PLG treatments were lower (P < 0.05) in thigh and leg cooking losses. The PLG treatment presented the highest values (P < 0.05) for breast-meat redness, saturation index, shear force, odor, taste, and overall sensory acceptability. The LBS was higher (P < 0.05) for breast-meat shear force, cohesiveness and resilience, but lower (P <0.05) for sensory attributes. Mexican oregano essential oils at 400 mg/L can serve as natural alternative additives in DWt to improve broiler production and meat quality

Antitumor efficacy of silver nanoparticles reduced with β-D-glucose as neoadjuvant therapy to prevent tumor relapse in a mouse model of breast cancer

Introduction: Neoadjuvant therapy constitutes a valuable modality for diminishing tumor volume prior to surgical resection. Nonetheless, its application encounters limitations in the context of recurrent tumors, which manifest resistance to conventional treatments. Silver nanoparticles (AgNPs) have emerged as a promising alternative for cancer treatment owing to their cytotoxic effects.Methods: Cellular viability was assessed by Alamar blue assay in 4T1 breast cancer cell line. Silver biodistribution was detected by an inductively coupled plasma optical emission spectrometer in an in vivo mice model. For neoadjuvant evaluation, mice were randomized and treated intratumoral with AgNPs-G or intraperitoneally with doxorubicin (DOX) as a control. Recurrence was determined after 170 days by counting lung metastatic nodules (dyed with Bouin solution) with histological confirmation by H&amp;E. Masson’s stain, Ki67 immunohistochemistry, and a TUNEL assay were performed in lungs from treated mice.Results: AgNPs-G reduced 4T1 cell viability and in an ex vivo assay the AgNPs-G decreased the tumor cell viability. After intravenous administration of AgNPs-G were detected in different organs. After intratumor administration, AgNPs-G are retained. The AgNPs-G treatment significantly reduced tumor volume before its surgical resection. AgNPs-G reduced the development of lung metastatic nodules and the expression of Ki67. TUNEL assay indicated that AgNPs-G didn’t induce apoptosis.Conclusions: We concluded that intratumor administration of AgNPs-G reduced tumor volume before surgical resection, alongside a reduction in lung metastatic nodules, and Ki67 expression. These findings provide valuable insights into the AgNPs-G potential for intratumor and neoadjuvant cancer therapies. However, further research is needed to explore their full potential and optimize their use in clinical settings

Akkermansia and Microbial Degradation of Mucus in Cats and Dogs : Implications to the Growing Worldwide Epidemic of Pet Obesity

Akkermansia muciniphila is a mucin-degrading bacterium that has shown the potential to provide anti-inflammatory and anti-obesity effects in mouse and man. We here focus on companion animals, specifically cats and dogs, and evaluate the microbial degradation of mucus and its health impact in the context of the worldwide epidemic of pet obesity. A literature survey revealed that the two presently known Akkermansia spp., A. muciniphila and A. glycaniphila, as well as other members of the phylum of Verrucomicrobia seem to be neither very prevalent nor abundant in the digestive tract of cats and dog. While this may be due to methodological aspects, it suggests that bacteria related to Akkermansia are not the major mucus degraders in these pets and hence other mucus-utilizing taxa may deserve attention. Hence, we will discuss the potential of these endogenous mucus utilizers and dietary interventions to boost these as well as the use of Akkermansia spp. related bacteria or their components as strategies to target feline and canine obesity.Peer reviewe

Nutritive value of "maniçoba" for sheep and goat

Quatorze animais, sendo sete caprinos e sete ovinos, adultos, machos, castrados, foram utilizados para avaliar o valor nutritivo da maniçoba (Manihot pseudoglaziovii). Todos os animais foram alojados em gaiolas de metabolismo por um período de adaptação de 14 dias e sete de coleta total de fezes e urina. O consumo da forrageira foi “ad libitum”, e os animais tiveram livre acesso à água e sal mineral. Os teores de proteína bruta e digestível, fibra em detergente neutro e energia digestível foram, respectivamente, de 99,3 e 97,6 g/kg0,75 /dia e de 190,1 e 204,7 kcal/ kg0,75 /dia. A digestibilidade da matéria seca foi de -1,3 e 0,16 g/dia para caprinos e ovinos, respectivamente. Entre caprinos e ovinos, não foi detectada diferença significativa (P>0,05), para nenhuma das variáveis estudadas. Os resultados são sugestivos que a proteína da maniçoba é de baixa degradabilidade.Fourteen adult castrated, male, seven goats and seven sheep, were used to evaluate the nutritive value of “maniçoba” (Manihot pseudoglaziovii). All animals were kept in individual metabolism cages for a period of 21 days, 14 days for adaptation and seven days of total feces and urine collection. Forage was offered “ad libitum” and the animals had free access to water and to a mineral-salt mix. Contents of crude and digestible protein, neutral detergent fiber and digestible energy were 12% and 5.25%; 58.6% and 2.0 Mcal/kg of dry matter respectively. Dry matter intake and digestibility by goats and sheep were 99.3 and 97.6 g/kg0.75 /day, and 190.1 and 209.7 kcal/kg0.75 day, respectively. Dry matter digestibility was 51.4 and 47.8% by goats and sheep, respectively. There was no difference (P>0.5) between goats and sheep for any variables analysed. Results suggest that the protein of “maniçoba” was of low degradability

Descriptive Bacterial and Fungal Characterization of Propolis Using Ultra-High-Throughput Marker Gene Sequencing

Bees harbor microorganisms that are important for host health, physiology, and survival. Propolis helps modulate the immune system and health of the colony, but little information is available about its microbial constituents. Total genomic DNA from samples of natural propolis from Apis mellifera production hives from four locations in Mexico were used to amplify a region of the 16S rRNA gene (bacteria) and the internal transcriber spacer (fungi), using PCR. The Illumina MiSeq platform was used to sequence PCR amplicons. Extensive variation in microbial composition was observed between the propolis samples. The most abundant bacterial group was Rhodopila spp. (median: 14%; range: 0.1%&ndash;27%), a group with one of the highest redox potential in the microbial world. Other high abundant groups include Corynebacterium spp. (median: 8.4%; 1.6%&ndash;19.5%) and Sphingomonas spp. (median: 5.9%; 0.03%&ndash;14.3%), a group that has been used for numerous biotechnological applications because of its biodegradative capabilities. Bacillus and Prevotella spp. alone comprised as much as 88% (53% and 35%, respectively) of all bacterial microbiota in one sample. Candida (2%&ndash;43%), Acremonium (0.03%&ndash;25.2%), and Aspergillus (0.1%&ndash;43%) were among the most abundant fungi. The results contribute to a better understanding of the factors associated with the health of Apis mellifera production hives

Comparative study with sheep and goats of the digestibility of a native legume in the semi-arid zone of Ceará, Brazil. II. In vivo digestibility of the silage of Cassia sp.

Dez caprinos Sem Raça Definida (SRD) e dez ovinos Santa Inés, machos, castrados, foram utilizados para avaliar o valor nutritivo da silagem de mata-pasto (Cassia spp). Os animais permaneceram em gaiolas de metabolismo por um período de 21 dias, sendo 14 de adaptado e 7 de coleta total de fezes. O consumo da silagem foi ad libitum. As concentrações de proteína bruta, fibra em detergente neutro (FDN) e lignina foram, respectivamente, de: 7,0, 55,3 e 7,8%. Não foi detectada diferença significativa (P> 0,05), entre caprinos e ovinos, em nenhuma das variáveis estudadas. O consumo de matéria seca foi de 72,0 e 86,8 g/kg0,75/dia para caprinos e ovinos, respectivamente. A digestibilidade da matéria seca e da FDN foram de 60,1, 60,4 e 43,0, 44,6% para caprinos e ovinos, respectivamente. O tempo de mastigação total foi de 925 min/dia para caprinos e de 990 min/dia para ovinos. Os resultados permitem concluir que caprinos e ovinos apresentaram a mesma eficiência de utilização do alimento e a silagem de mata-pasto apresentou potencial de utilizado para caprinos e ovinos.Ten SRD (undefined genotype) goats and ten sheep of the Santa Inês getiotypes, were used to evaluate the nutritive value of the mata-pasto (Cassia spp) silage. Experimental animals were kept in elevated metabolism crates for a 14-day adaptation period followed by a 7-day collection period of total faeces. All animals were adult males and castrated and they were given ad libitum access to water, mineral salt and forage consumption. There was no significant (PL0,05) difference between goat and sheep for any of the studied variables. Crude protein (CP), neutral detergent fiber (NDF) and KMnO lignin contents of the mata-pasto silage were, respectively, 7.0, 55.3 and 7.8%. Intake of dry matter and of digestible organic matter were, respectively, 72.0 and 43.0 g/kg0,75/day for goats and 86.8 and 53.8 g/kg0,75/day for sheep. NDF and dry matter digestibilities were in the order, of 60.1 and 60.4% and 43.0 and 44.6% for goats and sheep, respectively. Total chewing time was 925 min/day for goats and 990 min/day for sfteep. Both animal species showed similar feed utilization eficiency