Immunomodulation by Bifidobacterium animalis subsp. lactis Bb12: Integrative Analysis of miRNA Expression and TLR2 Pathway-Related Target Proteins in Swine Monocytes

Bifidobacterium animalis subsp. lactis Bb12 is a widely used probiotic that provides numerous health benefits to its host, many due to its immunomodulatory properties. Although the precise mechanism of modulation is still under investigation, several reports associate the interaction of TLR2 with components of the bacterial cell wall inducing a signaling cascade that culminates with the production of cytokines and co-stimulatory molecules. MicroRNAs (miRNAs) have emerged as important post-transcriptional regulators of immune responses, including those toward probiotics. In this study, we analyzed the miRNA expression profile in swine monocytes exposed to Bb12 by using an anti-TLR2 blocking strategy and Bb12 involvement in the regulation of the TLR2 pathway. As a result, the expression of 40 miRNAs was influenced by the treatments (p < 0.01), and 15 differentially expressed miRNAs with validated miRNA–mRNA interactions with around 26 proteins related to the TLR2 pathway were identified. The miRNAs upregulated in response to Bb12 included miR-15a-5p, miR-16-5p, miR-26a-5p, miR-29b-3p, and miR-30d-5p, and the following showed downregulation: miR-181a-5p, miR-19b-3p, miR-21-5p, miR-23a-5p, and miR-221-3p. The expression of let-7c-5p, let-7f-5p, miR-146b-5p, miR-150-5p, and miR-155-5p was increased by Bb12 only when TLR2 was blocked. The identified miRNA common targets were downstream proteins from bacterial recognition via TLR2, such as MyD88, TRAF6, and MAPK members; transcription factors such as NF-κB and AP-1; and cytokines such as IL-6, IL-10, and TNF-α. TLR2 participation was abrogated by anti-TLR2 antibody and suggests that bacterial recognition is complemented by other receptors since there were still changes in the microtranscriptome.

Microbiome-MX 2018: microbiota and microbiome opportunities in Mexico, a megadiverse country

A weekly conference series paired with lectures entitled "Microbiome-MX: exploring the Microbiota and Microbiome Research in Mexico" was organized to provide a multidisciplinary overview of the most recent research done in Mexico using high-throughput sequencing. Scientists and postgraduate students from several disciplines such as microbiology, bioinformatics, virology, immunology, nutrition, and medical genomics gathered to discuss state of the art in each of their respective subjects of expertise, as well as advances, applications and new opportunities on microbiota/microbiome research. In particular, high-throughput sequencing is a crucial tool to understand the challenges of a megadiverse developing country as Mexico, and moreover to know the scientific capital and capabilities available for collaboration. The conference series addressed three main topics important for Mexico: i) the complex role of microbiota in health and prevalent diseases such as obesity, diabetes, inflammatory bowel disease, tuberculosis, HIV, autoimmune diseases and gastric cancer; ii) the use of local, traditional and prehispanic products as pre/probiotics to modulate the microbiota and improve human health; and iii) the impact of the microbiota in shaping the biodiversity of economically important terrestrial and marine ecosystems. Herein, we summarize the contributions that Mexican microbiota/microbiome research is making to the global trends, describing the highlights of the conferences and lectures, rather than a review of the state-of-the-art of this research. This meeting report also presents the efforts of a multidisciplinary group of scientist to encourage collaborations and bringing this research field closer for younger generations.

Body Composition in Mexican Adults by Air Displacement Pletismography (ADP) with the Bod-Pod and Deuterium Oxide Dilution Using Infrared Spectroscopy (IRS-DOD)

Thirty four subjects (13 men and 21 women), 24 to 70 years old from northern Mexico, were measured for body density by air displacement plethysmography (ADP) with the BOD-POD, and for total body water by deuterium oxide dilution and infrared spectroscopy (IRS-DOD). Subjects were given a 30 g dose of deuterium oxide. Saliva samples were filtered, sublimated, and deuterium was measured using a Miran 1 FF, IRS. Linear regression of the fat mass (FM) derived from both methods showed that the intercept (0.071) was not different from zero (p = .96) and the slope was 0.96 (p < .0001) demonstrating the techniques to be equivalent. Further, mean FM was 26.7 ± 12.4 and 25.6 ± 12.4 kg, for IRS-DOD and ADP techniques, respectively (p = .08). Precision analysis by the model R2 showed that 92.3% of the variability was explained (SEM = 3.4 kg). Bland-Altman analysis showed no significant bias (r = 0.017; p = .93). Mean difference between methods was −1.08 (CI: −2.3 to + 0.13) kg FM.

Measurement of Deuterium Oxide by Infrared Spectroscopy and Isotope Ratio Mass Spectrometry for Quantifying Daily Milk Intake in Breastfed Infants and Maternal Body Fat

Measurements of deuterium oxide concentrations (DOC) in saliva by infrared spectroscopy (IRS) and isotope ratio mass spectrometry (IRMS) were compared for the calculation of infants’ milk intake and maternal body fat. Deuterium oxide (30g) was given to the mother. DOC by IRS and IRMS were 340 ± 209 and 345 ± 202 ppm. The mean difference between both methods (4.62 ± 76.3) was not different from zero (p = .57). Bland and Altman analysis showed no significant overall bias (r = 0.10; p = .33), but dispersion within the limits of agreement. The mean milk intake in the infants’ by IRS and IRMS were 624 ± 296 g/day and 634 ± 327 g/day (p = .642) and the mothers’ mean body fat were 31.3 ± 12% and 31.5 ± 13% (p = .755). The results appear to be the same for milk intake and body fat by the two methods and no evidence of bias was found.

Use of real-time polymerase chain reaction to identify Entamoeba histolytica in schoolchildren from northwest Mexico

INTRODUCTION

Entamoeba histolytica, E. dispar, and E. moshkovskii are morphologically identical, but intestinal amebiasis is caused only by E. histolytica. Mexico is among the countries with high amebae infection rates, although the contribution of pathogenic amoeba to the total detected cases remains unknown, especially in the northwestern dry region. Therefore, the aim of this study was to identify the actual prevalence of E. histolytica using real-time polymerase chain reaction (PCR) in schoolchildren of  northwestern Mexico.

METHODOLOGY

Participants were children from five public elementary schools in the low-socioeconomic-level suburban areas of Hermosillo, Sonora, Mexico. One stool sample was collected from each child and analyzed by the Faust technique for Entamoeba spp. and by real-time PCR for E. histolytica.

RESULTS

Analysis of stool  samples from 273 children (9.0 ± 1.5 years of age) resulted in 25 (9.2%) positive for E. histolytica/E. dispar/E. moshkovskii by the Faust technique; of these, 3 were positive for E. histolytica by real-time PCR. In addition, 2 samples that were negative for E. histolytica/E. dispar/E. moshkovskii by the Faust technique were positive by real-time PCR.

CONCLUSIONS

The actual prevalence of E. histolytica in our study population was 1.8%, which is lower than those reported in previous studies in other Mexican regions.

A population-wide applicable HLA-DQ2 and DQ8 genotyping using DNA from dried blood spots and duplex allele-specific qPCR amplification

Genotyping of HLA-DQ2 and DQ8 haplotypes is important for diagnosis or for screening of early risk detection of celiac disease or type 1 diabetes. Usually, venous blood DNA extraction and expensive and time consuming amplification are used, that hinder population-wide studies. We assayed a friendly HLA-DQ2 and DQ8 genotyping procedure using a combination of DNA from dried blood spot (DBS) and duplex allele-specific qPCR amplification using SYBR Green. DNA was extracted using home-made buffers and compared to an extraction commercial kit. Duplex reactions by qPCR were designed using each Tm allele amplicon for reference samples (positive HLA-DQ2 or DQ8) with allele-specific primers. DBS samples from 558 children (7.99 ± 2.47 y) were collected. The DNA final yield obtained by the home-made extractive procedure was higher than from the commercial kit (1.11 ± 0.56 vs 0.23 ± 0.14 μg), while the quality was similar for both DNA samples. There was concordance in the amplification profiles for DNA samples obtained with both methods. All of four alleles from DQ2 and DQ8 haplotypes were accurately identified in duplex reactions. By using DBS samples and DNA extraction home-made procedure, the costs were reduced by 60%. The whole procedure is cost-effective for HLA-DQ2 and DQ8 genotyping.

Transamidation of gluten proteins during the bread-making process of wheat flour to produce breads with less immunoreactive gluten

Due to an increasing incidence of celiac disease (CD) and other gluten-related disorders, different gluten-free breads have been developed using starches and additives as a substitute for gluten. Thus, patients miss not only the taste and aroma of wheat bread but also risk their sensitive intestines. Therefore, modifying gluten to avoid an immune response in CD and its application to baking is in progress. The aim of the study was to enzymatically modify gluten on wheat flour, during bread-making avoiding the use of additives, to reduce immunoreactivity, preserving its properties. Microbial transglutaminase (mTG) or chymotrypsin (ChT) was used to bind lysine or valine to gluten proteins in a model system. The best conditions were directly applied to wheat flour for bread-making with and without punching at 45 min. Subsequently, the rheological properties of the doughs, specific volume of the loaves, immunoreactive gluten content and modification of the extracted proteins were evaluated. ChT-treated breads presented a better appearance with a more homogeneous crumb, higher specific volume values (3.34-4.25 cm(3) g(-1)) and higher reactive gluten reduction (up to 71%) than the mTG-treated ones (1.23-2.66 cm(3) g(-1)) with only a 42% reactive gluten reduction. Thus, transpeptidation during bread-making is a promising technology, although it is necessary to improve the modification process to obtain the reactive gluten reduction required in breads for the treatment of CD patients and other gluten-related disorders.

Development and evaluation of a nutritionally enhanced multigrain tortilla snack

An increased consumption of healthy foods to reduce chronic diseases risks is needed. We developed and evaluated a multigrain snack as a nutritive alternative to the highly consumed corn tortilla chips. Corn, wheat, and chickpea grains were boiled in 1% calcium oxide solution, steeped, washed, and ground before being mixed with soy protein isolate and oat flour to prepare the multigrain masa. Multigrain tortillas were moulded, baked, dried, and fried. Proximate composition, dietary fiber, protein quality, sensorial, and textural properties were evaluated. A commercial tortilla chip was used as control. The multigrain snack contained 153% more protein, 53% more dietary fiber, and 43 % less fat than commercial tortilla chips. Its lysine and isoleucine contents helped to increase the corrected-net protein utilization by 10%, while digestibility increased from 83.5 to 91.8% as compared to commercial tortilla chips. The mean breaking force was 6,082 g for the multigrain snack and 4,780 g for the commercial tortilla chips. The mean acceptability score for the multigrain snack was 12.1 (unstructured line scale 0-15 cm), and 82% of the panelists rated the snack as acceptable. In conclusion, a nutritionally enhanced multigrain tortilla snack was developed which provides significantly more dietary fiber and protein and less fat than traditional commercial corn tortilla chips, but with comparable appearance and high acceptability.

Gluten-free breads and cookies of raw and popped amaranth flours with attractive technological and nutritional qualities

Gluten-free bakery foodstuffs are a challenge for technologists and nutritionists since alternative ingredients used in their formulations have poor functional and nutritional properties. Therefore, gluten-free bread and cookies using raw and popped amaranth, a grain with high quality nutrients and promising functional properties, were formulated looking for the best combinations. The best formulation for bread included 60-70% popped amaranth flour and 30-40% raw amaranth flour which produced loaves with homogeneous crumb and higher specific volume (3.5 ml/g) than with other gluten-free breads. The best cookies recipe had 20% of popped amaranth flour and 13% of whole-grain popped amaranth. The expansion factor was similar to starch-based controls and the hardness was similar (10.88 N) to other gluten-free cookies. Gluten content of the final products was around 12 ppm. The functionality of amaranth-based doughs was acceptable although hydrocolloids were not added and the final gluten-free products had a high nutritional value.

Nutritional and technological evaluation of an enzymatically methionine-enriched soy protein for infant enteral formulas

Enzymatically modified soy proteins have the amino acid profile and functional properties required for dietary support. The objective of this study was to evaluate the nutritional and technological properties of an enzymatically modified soy protein ultrafiltered fraction with bound methionine (F(1-10)E) to be used as a protein ingredient for infant enteral formulas. F(1-10)E was chemically characterized and biologically evaluated. Thirty-six weaning Wistar rats were fed during 3 weeks with a 4% casein-containing diet. Rats were divided into three groups and recovered for 3 weeks with 18% protein-containing diets based on: (1) F(1-10)E, (2) casein or (3) soy isolate+methionine. Nutritional indicators were weight gain, protein efficiency ratio, plasma proteins, apparent digestibility and protein in the carcass. Additionally, F(1-10)E was added as a protein ingredient of an enteral formula, and its sensory and rheological properties were compared with a hydrolyzed-whey protein commercial formula. F(1-10)E contained 68% protein and 5% sulphur amino acids, with 60% of peptides </=6 kDa. Casein-based and F(1-10)E-based diets were comparable (P>0.05) in weight gain (108 g and 118 g, respectively), protein efficiency ratio (2.7), apparent digestibility (93% and 95%), plasma proteins (5.7 mg/100 ml) and carcass protein (61%), and better than soy isolate-based+methionine diet (P<0.05). Viscosity of the commercial formula and our formula was similar during a 24-h period. Sensory acceptability was 8 for our formula and 3.5 for the commercial one, on a scale of 1-10 (P<0.05). Due to its nutritional, sensorial and rheological properties, F(1-10)E could be used as a protein source in infant enteral formulas.

Tetany caused by chronic diarrhea in a child with celiac disease: A case report

There is no awareness about celiac disease (CD) in Mexico. A 2.9 year old mestizo boy was admitted to a Mexican hospital with muscle cramps and fine tremors. He suffered chronic diarrhea, abdominal distention, hypotrophic limbs, stunting and wasting, and presented hypocalcemia, anemia and high titers of serological markers. Diagnosis of CD was confirmed by a duodenal biopsy. After replacement of calcium and a gluten-free diet, the symptoms resolved within 6 weeks. After 2-months, serum analyses, anthropometric data as well as antibodies titers were normal after 4 years. CD screening tests are needed in chronic diarrhea for any ethnicity patients.

Caerulin-induced pancreatitis in rats: Histological and genetic expression changes from acute phase to recuperation

AIM: To study the histological and pancreatitis-associated protein mRNA accumulation changes of pancreas from acute phase of caerulin-induced pancreatitis to recuperation in rats.

METHODS: Acute pancreatitis was induced by caerulein in male Wistar rats and followed up for 90 d by histological and mRNA analyses of pancreas. Pancreases were dissected at 0, 9, 24 h and 3, 5, 15, 30, 60, 90 d post-induction. Edema (E), polymorphonuclear neutrophil (PMN) infiltration, cytoplasmic vacuolization (V), zymogen granule depletion (ZD) and acinar disorganization (AD) were microscopically evaluated. Accumulation of pancreatitis-associated protein (PAP) and L13A mRNAs were quantified by real-time PCR.

RESULTS: The main histological changes appeared at 9 h post-induction for PMN infiltration and cytoplasmic V, while at 24 h and 3 d for E and ZD, respectively. All the parameters were recovered after 5 d, except for ZD which delayed more than 30 d. The main AD was observed after 15 d and values returned to normal after 30 d. Similarly to histological changes, accumulation of the PAP mRNA was increased at 9 h with the highest accumulation at 24 h and differences disappeared after 5 d.

CONCLUSION: From the acute phase to recuperation of pancreatitis, regeneration and re-differentiation of pancreas occur and PAP expression is exclusively an acute response of pancreatitis.

Body composition in Mexican adults by air displacement plethysmography (ADP) with the BOD-POD and deuterium oxide dilution using infrared spectroscopy (IRS-DOD)

Thirty four subjects (13 men and 21 women), 24 to 70 years old from northern Mexico, were measured for body density by air displacement plethysmography (ADP) with the BOD-POD, and for total body water by deuterium oxide dilution and infrared spectroscopy (IRS-DOD). Subjects were given a 30 g dose of deuterium oxide. Saliva samples were filtered, sublimated, and deuterium was measured using a Miran 1 FF, IRS. Linear regression of the fat mass (FM) derived from both methods showed that the intercept (0.071) was not different from zero (p = .96) and the slope was 0.96 (p < .0001) demonstrating the techniques to be equivalent. Further, mean FM was 26.7 +/- 12.4 and 25.6 +/- 12.4 kg, for IRS-DOD and ADP techniques, respectively (p = .08). Precision analysis by the model R2 showed that 92.3% of the variability was explained (SEM = 3.4 kg). Bland-Altman analysis showed no significant bias (r = 0.017; p = .93). Mean difference between methods was -1.08 (CI: -2.3 to + 0.13) kg FM.

Measurement of deuterium oxide by infrared spectroscopy and isotope ratio mass spectrometry for quantifying daily milk intake in breastfed infants and maternal body fat

Measurements of deuterium oxide concentrations (DOC) in saliva by infrared spectroscopy (IRS) and isotope ratio mass spectrometry (IRMS) were compared for the calculation of infants' milk intake and maternal body fat. Deuterium oxide (30 g) was given to the mother. DOC by IRS and IRMS were 340 +/- 209 and 345 +/- 202 ppm. The mean difference between both methods (4.62 +/- 76.3) was not different from zero (p = .57). Bland and Altman analysis showed no significant overall bias (r = 0.10; p = .33), but dispersion within the limits of agreement. The mean milk intake in the infants' by IRS and IRMS were 624 +/- 296 g/day and 634 +/- 327 g/day (p = .642) and the mothers' mean body fat were 31.3 +/- 12% and 31.5 +/- 13% (p = .755). The results appear to be the same for milk intake and body fat by the two methods and no evidence of bias was found.