Potential of fermented foods and their metabolites in improving gut microbiota function and lowering gastrointestinal inflammation.

Foods prepared using microbial conversion of major and minor food components, which are otherwise known as fermented foods continue to impact human health. The live microorganisms and transformed metabolites can also have a deep influence on the gut microbiota, the multifaceted population of microorganisms dwelling inside the gut play a key role in wellbeing of an individual. The probiotic strains delivered through the consumption of fermented food and other bioactive components such as polyphenolic metabolites, bioactive peptides, short-chain fatty acids and others including those produced via gut microbiota mediated transformations have been proposed to balance the gut microbiota diversity and activity, and also to regulate the inflammation in the gut. However, little is known about such effects and only a handful of fermented foods have been explored to date. We herein review the recent knowledge on the dysbiotic gut microbiota linking to major gut inflammatory diseases. Also, evidences that fermented food consumption modulates the gut microbiota, and its impact on the gut inflammation and inflammatory diseases have been discussed. © 2024 Society of Chemical Industry.

Production and characterization of anti-hypertensive and anti-diabetic peptides from fermented sheep milk with anti-inflammatory activity: in vitro and molecular docking studies.

BACKGROUND: The present study aimed to evaluate the anti-hypertensive and anti-diabetic activities from biologically active peptides produced by fermented sheep milk with Lacticaseibacillus paracasei M11 (MG027695), as well as to purify and characterize the angiotensin-converting enzyme (ACE) inhibitory and anti-diabetic peptides produced from fermented sheep milk. RESULTS: After 48 h of fermentation at 37 °C, sheep milk demonstrated significant changes in anti-diabetic effects and ACE-I effects, with inhibition percentages observed for ACE inhibition (76.32%), α-amylase (70.13%), α-glucosidase (70.11%) and lipase inhibition (68.22%). The highest level of peptides (9.77 mg mL-1) was produced by optimizing the growth conditions, which included an inoculation rate of 2.5% and a 48 h of incubation period. The comparison of molecular weight distributions among protein fractions was conducted through sodium dodecyl-sulfate polyacrylamide gel electrophoresis analysis, whereas spots were separated using 2D gel electrophoresis according to both the molecular weight and pH. Peptide characterization with ultra-filtration membranes at 3 and 10 kDa allowed the study to assess molecular weight-based separation. Nitric oxide generated by lipopolysaccharide and the secretion of pro-inflammatory cytokines in RAW 264.7 immune cells were both inhibited by sheep milk fermented with M11. Fourier-transform infrared spectroscopy was employed to assess changes in functional groups after fermentation, providing insights into the structural changes occurring during fermentation. CONCLUSION: The present study demonstrates that fermentation with L. paracasei (M11) led to significant changes in fermented sheep milk, enhancing its bioactive properties, notably in terms of ACE inhibition and anti-diabetic activities, and the generation of peptides with bioactive properties has potential health benefits. © 2024 Society of Chemical Industry.

Production of mulberry wine using selenium-enriched Saccharomyces cerevisiae: implications from sensory analysis, phytochemical and antioxidant activities.

The present study aims to evaluate the quality of chemical, sensory properties and antioxidant potential of mulberry wine using selenium-enriched yeasts employing eight different methods (MW1-MW8). The selenium-enriched yeast significantly (p < 0.05) increased phytochemical profiles, flavor, quality and antioxidant capacity. The most effective method for raising the selenium level of mulberry wine was using L-seMC (MW5). Mulberry wine color was attributed to the anthocyanins and phytochemical composition with selenium content. DPPH and ABTS radical scavenging activity varied with change in treatment methods suggesting their impact on antioxidant activity. Total selenium content on L-SeMC supplementation proved a significant correlation between selenium content with total anthocyanin content, total polyphenol content and flavonoid content. Sensory analysis by electronic nose exhibited MW2 with high response value in the W2S sensor showing high alcohol concentration. GC-MS analysis showed the presence of 57 volatile aromatic compounds comprehended by esters and alcohol (isoamyl alcohol, 2-methylbutanol, 2,3-butanediol, and phenethyl alcohol). Principal component analysis affirms the response values for four categorical score values with reliability and consistency for all the parameters, significantly. Thus, the workflow demonstrates a simpler, cost-effective traditional methodology for rationalized outcomes. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05847-4.

The way forward to produce nutraceuticals from agri-food processing residues: obstacle, solution, and possibility.

Food matrices contain bioactive compounds that have health benefits beyond nutritional value. The bulk of bioactive chemicals are still present in agro-industrial by-products as food matrices. Throughout the food production chain, there is a lot of agro-industrial waste that, if not managed effectively, could harm the environment, company, and how nutritiously and adequately people eat. It's important to establish processes that maximise the use of agro-industrial by-products, such as biological technologies that improve the extraction and acquisition of bioactive compounds for the food and pharmaceutical industries. As opposed to nonbiological processes, biological procedures provide high-quality, bioactive extracts with minimum toxicity and environmental impact. Fermentation and enzymatic treatment are biological processes for obtaining bioactive compounds from agro-industrial waste. In this context, this article summarises the principal bioactive components in agro-industrial byproducts and the biological methods employed to extract them. In this review efficient utilization of bioactive compounds from agro-industrial waste more effectively in food and pharmaceutical industries has been described.

Molecular binding mechanism and novel antidiabetic and anti-hypertensive bioactive peptides from fermented camel milk with anti-inflammatory activity in raw macrophages cell lines.

The investigation was to determine the effect of camel milk fermented with Limosilactobacillus fermentum KGL4 (MTCC 25515) on ACE-inhibiting, anti-inflammatory, and diabetes-preventing properties and also to release the novel peptides with antidiabetic and anti-hypertensive attributes with molecular interaction studies. Growth conditions were optimised on the basis of total peptide production by inoculating the culture in camel milk at different rates (1.5, 2.0, and 2.5%) along with different incubation periods (12, 24, 36, and 48 h). However, after 48 h of fermentation with a 2.5% rate of inoculum, the highest proteolytic activity was obtained. Reverse phase high-pressure liquid chromatography (RP-HPLC) was used to calculate the % Rpa from permeates of 3 kDa and 10 kDa fractions. Molecular weight distributions of fermented and unfermented camel milk protein fractions were compared using SDS-PAGE. Spots obtained from 2D gel electrophoresis were separated on the basis of pH and molecular weight. Spots obtained from 2D gel were digested with trypsin, and the digested samples were subjected to RP-LC/MS for the generation of peptide sequences. The inhibition of tumour necrosis factor alpha, interleukin-6, and interleukin-1 during fermentation was studied using RAW 264.7 macrophages. In the study, fermented camel milk with KGL4 (CMKGL4) inhibited LPS-induced nitric oxide (NO) production and pro-inflammatory cytokine production (TNF-α, IL-6, and IL-1ß) by the murine macrophages. The results showed that the peptide structures (YLEELHRLNK and YLQELYPHSSLKVRPILK) exhibited considerable binding affinity against hPAM and hMGA during molecular interaction studies.

Lactic acid bacteria in the functional food industry: biotechnological properties and potential applications.

With the growing demand for functional foods having better nutraceutical properties, lactic acid bacteria (LAB) has become an important industrial microorganism. LAB play a significant role in the functional food industry by exhibiting probiotic properties and has the ability to produce various biologically active metabolites such as γ-aminobutyric acid (GABA), exopolysaccharides (EPSs), conjugated linoleic acid (CLA), bacteriocins, reuterin and reutericyclin, which provides enhanced nutraceutical properties to the final food products. LAB are also known to produce several specific enzymes essential for producing substrate-derived bioactive compounds, such as polyphenols, bioactive peptides, inulin-type fructans and ß-glucans, fatty acids, and polyols. These compounds exhibit many health benefits, including better mineral absorption, oxidative stress protection, blood glucose and cholesterol-lowering properties, prevention of gastrointestinal tract infections and improved cardiovascular function. Further, metabolically engineered LAB have been widely used for the nutritive enhancement of different food products and the application of CRISPR-Cas9 holds tremendous potential for the engineering of food cultures. This review provides an overview of the use of LAB as probiotics, its application in producing fermented foods and nutraceutical products, and its health benefits on the host.

iTRAQ based proteomic analysis of rice lines having single or stacked blast resistance genes: Pi54/Pi54rh during incompatible interaction with Magnaporthe oryzae.

Deployment of single or multiple blast resistance (R) genes in rice plant is considered to be the most promising approach to enhance resistance against blast disease caused by fungus Magnaporthe oryzae. At the proteome level, relatively little information about R gene mediated defence mechanisms for single and stacking resistance characteristics is available. The overall objective of this study is to look at the proteomics of rice plants that have R genes; Pi54, Pi54rh and stacked Pi54 + Pi54rh in response to rice blast infection. In this study 'isobaric tag for relative and absolute quantification' (iTRAQ)-based proteomics analysis was performed in rice plants at 72-h post inoculation with Magnaporthe oryzae and various differentially expressed proteins were identified in these three transgenic lines in comparison to wild type during resistance response to blast pathogen. Through STRING analysis, the observed proteins were further examined to anticipate their linked partners, and it was shown that several defense-related proteins were co-expressed. These proteins can be employed as targets in future rice resistance breeding against Magnaporthe oryzae. The current study is the first to report a proteomics investigation of rice lines that express single blast R gene Pi54, Pi54rh and stacked (Pi54 + Pi54rh) during incompatible interaction with Magnaporthe oryzae. The differentially expressed proteins indicated that secondary metabolites, reactive oxygen species-related proteins, phenylpropanoid, phytohormones and pathogenesis-related proteins have a substantial relationship with the defense response against Magnaporthe oryzae. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01327-3.

Metagenomic views on taxonomic and functional profiles of the Himalayan Tsomgo cold lake and unveiling its deterzome potential.

Cold habitat is considered a potential source for detergent industry enzymes. This study aims at the metagenomic investigation of Tsomgo lake for taxonomic and functional annotation, unveiling the deterzome potential of the residing microbiota at this site. The present investigation revealed molecular profiling of microbial community structure and functional potential of the high-altitude Tsomgo lake samples of two different temperatures, harvested during March and August. Bacteria were found to be the most dominant phyla, with traces of genomic pieces of evidence belonging to archaea, viruses, and eukaryotes. Proteobacteria and Actinobacteria were noted to be the most abundant bacterial phyla in the cold lake. In-depth metagenomic investigation of the cold aquatic habitat revealed novel genes encoding detergent enzymes, amylase, protease, and lipase. Further, metagenome-assembled genomes (MAGs) belonging to the psychrophilic bacterium, Arthrobacter alpinus, were constructed from the metagenomic data. The annotation depicted the presence of detergent enzymes and genes for low-temperature adaptation in Arthrobacter alpinus. Psychrophilic microbial isolates were screened for lipase, protease, and amylase activities to further strengthen the metagenomic findings. A novel strain of Acinetobacter sp. was identified with the dual enzymatic activity of protease and amylase. The bacterial isolates exhibited hydrolyzing activity at low temperatures. This metagenomic study divulged novel genomic resources for detergent industry enzymes, and the bacterial isolates secreting cold-active amylase, lipase, and protease enzymes. The findings manifest that Tsomgo lake is a potential bioresource of cold-active enzymes, vital for various industrial applications.

Cold-adaptive traits identified by comparative genomic analysis of a lipase-producing Pseudomonas sp. HS6 isolated from snow-covered soil of Sikkim Himalaya and molecular simulation of lipase for wide substrate specificity.

The genomic analysis of industrially important bacteria can help in understanding their capability to withstand extreme environments and shed light on their metabolic capabilities. The whole genome of a previously reported broad temperature active lipase-producing Pseudomonas sp. HS6, isolated from snow-covered soil of the Sikkim Himalayan Region, was analyzed to understand the capability of the bacterium to withstand cold temperatures and study its lipolytic nature. Pseudomonas sp. HS6 was found to be psychrotolerant with an optimal growth temperature ranging between 25 and 30 °C, with the ability to grow at 5 °C. The genome harbours various cold-adaptation genes, such as cold-shock proteins, fatty acid alteration, and cold stress-tolerance genes, supporting the psychrotolerant nature of the organism. The comparative analysis of Pseudomonas sp. HS6 genome showed the presence of amino acid substitutions in genes that favor efficient functioning and flexibility at cold temperatures. Genome mining revealed the presence of four triacylglycerol lipases, among which the putative lipase 3 was highly similar to the broad temperature-active lipase purified and characterized in our previous study. In silico studies of putative lipase 3 revealed broad substrate specificity with partial and no inhibition of the enzyme activity in the presence of PMSF and orlistat. The presence of genes associated with cold adaptations and true lipases with activity at broad temperature and substrate specificity in the genome of Pseudomonas sp. HS6 makes this bacterium a suitable candidate for industrial applications.

Fermentation of black soybean with Bacillus spp. for the production of kinema: changes in antioxidant potential on fermentation and gastrointestinal digestion.

Black soybean was fermented with four different potential Bacillus spp., including Bacillus licheniformis K1G, Bacillus subtilis K2B, Bacillus amyloliquefaciens K2G and Bacillus subtilis K2M, isolated from kinema, a traditionally fermented soybean product of Sikkim. Enhancement of antioxidant activity was observed with DPPH radical scavenging activity, reducing power potential and total antioxidant activity in methanolic as well as water extracts. Overall antioxidant activities were found to be higher in fermented black soybean in comparison to yellow soybean, showing its potential for production of kinema. Further, black soybean fermented using different starter was subjected to gastrointestinal digestion using pepsin and pancreatin. Upon gastrointestinal digestion of fermented black soybean changes in antioxidant activity was observed that was found to be reliant on the species and strains applied for fermentation as starter culture. Among different starters used for fermentation, black soybean fermented using B. subtilis K2M had higher DPPH radical scavenging and reducing power activity on gastrointestinal digestion. This study concludes that B. subtilis K2M can be applied for fermentation of black soybean for production of kinema as well as bioactive protein hydrolysates. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05144-y.

Molecular Cytogenetic Classification of Down Syndrome and Screening of Somatic Aneuploidy in Mothers.

Down Syndrome (DS) caused by trisomy 21 results in various congenital and developmental complications in children. It is crucial to cytogenetically diagnose the DS cases early for their proper health management and to reduce the risk of further DS childbirths in mothers. In this study, we performed a cytogenetic analysis of 436 suspected DS cases using karyotyping and fluorescent in situ hybridization. We detected free trisomies (95.3%), robertsonian translocations (2.4%), isochromosomes (0.6%), and mosaics (1.2%). We observed a slightly higher incidence of DS childbirth in younger mothers compared to mothers with advanced age. We compared the somatic aneuploidy in peripheral blood of mothers having DS children (MDS) and control mothers (CM) to identify biomarkers for predicting the risk for DS childbirths. No significant difference was observed. After induced demethylation in peripheral blood cells, we did not observe a significant difference in the frequency of aneuploidy between MDS and CM. In conclusion, free trisomy 21 is the most common type of chromosomal abnormality in DS. A small number of DS cases have translocations and mosaicism of chromosome 21. Additionally, somatic aneuploidy in the peripheral blood from the mother is not an effective marker to predict DS childbirths.

Decoding the complexity of circular RNAs in cardiovascular disease.

Circular RNAs (circRNAs) are a new class of covalently circularized noncoding RNAs widely expressed in the human heart. Emerging evidence suggests they have a regulatory role in a variety of cardiovascular diseases (CVDs). This review's current focus includes our understanding of circRNA classification, biogenesis, function, stability, degradation mechanisms, and their roles in various cardiovascular disease conditions. Our knowledge of circRNA, the relatively recent member of the noncoding RNA family, is still in its infancy; however, recent literature proposes circRNAs may be promising targets for the understanding and treatment of CVD.

Microwave-assisted efficient synthesis of pyrazole-fibrate derivatives as stimulators of glucose uptake in skeletal muscle cells.

The design and synthesis of a series of pyrazolo[3,4-d]pyrimidinones containing fibrate side chains have been accomplished by utilizing the concept of molecular hybridization. All the synthesized compounds were evaluated for the glucose uptake stimulatory effect in L6 rat skeletal muscle cells. Four compounds (3f, 3g, 3j and 3q) were found to show significant stimulation of glucose uptake. Further these four compounds have been examined for their Glut4 translocation stimulatory effect in L6-Glut4myc myotubes. Compound 3q was found to exert maximum increase in GLUT4myc translocation.

Bioconservation of iron and enhancement of antioxidant and antibacterial properties of chicken gizzard protein hydrolysate fermented by Pediococcus acidilactici ATTC 8042.

BACKGROUND: The poultry industry is one of the fastest growing sectors, and it generates considerable quantities of chicken gizzards (CG) every day. However, due to their hard texture and high microbial load, and due to cultural beliefs, they are not preferred by consumers. Chicken gizzards are a substantial source of proteins, iron, and other nutrients, which can be used effectively to produce nutraceuticals, rich in peptides (antioxidants and antibacterial), bio-iron, essential free amino acids, and fatty acids vital for human health. RESULTS: Lactic acid fermentation of CG by Pediococcus acidilactici ATTC 8042 increased the antioxidant activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), azino-bis (3-ethylbenzothiaziline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) by up to 26 times compared with unfermented CG (P < 0.05). The amount of hydrolysis and solvents (ethanol and water) used for extracting protein hydrolysates significantly affected the antioxidant properties. Moreover, fermented CG showed a negligible reduction in bio-iron (2-3%) compared with heat-processed CG (85 °C for 15 min), in which bio-iron was reduced by up to 20.3% (P < 0.05). The presence of unsaturated fatty acids such as C20:4 and C22:4 n-6 indicated a low level of lipid oxidation. CONCLUSION: Fermented CG, with its reasonably high antioxidant and antibacterial activity, together with a substantial amount of bio-iron and other nutritional components can serve as a functional food or feed additive to reduce oxidative stress and to treat iron deficiency. © 2020 Society of Chemical Industry.

Biotechnological approaches for the production of designer cheese with improved functionality.

Cheese is a product of ancient biotechnological practices, which has been revolutionized as a functional food product in many parts of the world. Bioactive compounds, such as peptides, polysaccharides, and fatty acids, have been identified in traditional cheese products, which demonstrate functional properties such as antihypertensive, antioxidant, immunomodulation, antidiabetic, and anticancer activities. Besides, cheese-making probiotic lactic acid bacteria (LAB) exert a positive impact on gut health, aiding in digestion, and improved nutrient absorption. Advancement in biotechnological research revealed the potential of metabolite production with prebiotics and bioactive functions in several strains of LAB, yeast, and filamentous fungi. The application of specific biocatalyst producing microbial strains enhances nutraceutical value, resulting in designer cheese products with multifarious health beneficial effects. This review summarizes the biotechnological approaches applied in designing cheese products with improved functional properties.

Deciphering the role of microRNAs during Pi54 gene mediated Magnaporthe oryzae resistance response in rice.

The broad-spectrum resistance gene Pi54 confers resistance to multiple isolates of Magnaporthe oryzae in rice. In order to decipher the molecular mechanism underlying the Pi54 mediated resistance in rice line Taipei309 Pi54 (carrying Pi54), miRNAome study was performed at 24 h post-inoculation (hpi) with M. oryzae. A total of 222 known miRNAs representing 101 miRNA families were found in this study. Of these, 29 and 24 miRNAs were respectively up- and down-regulated in the resistant Taipei309 Pi54 . Defence response (DR) genes, like, NBSGO35, and OsWAK129b, and genes related to transcription factors were up-regulated in Taipei309 Pi54 line. The vast array of miRNA candidates identified here are miR159c, miR167c, miR2100, miR2118o, miR2118l, miR319a, miR393, miR395l, miR397a, miR397b, miR398, miR439g, miR531b, miR812f, and miR815c, and they manifest their role in balancing the interplay between various DR genes during Pi54 mediated resistance. We also validated miRNA/target gene pairs involved in hormone signalling, and cross-talk among hormone pathways regulating the rice immunity. This study suggests that the Pi54 gene mediated blast resistance is influenced by several microRNAs through PTI and ETI components in the rice line Taipei309 Pi54 , leading to incompatible host-pathogen interaction.

Production of angiotensin I converting enzyme inhibitory (ACE-I) peptides during milk fermentation and their role in reducing hypertension.

Fermented milk is a potential source of various biologically active peptides with specific health benefits. Angiotensin converting enzyme inhibitory (ACE-I) peptides are one of the most studied bioactive peptides produced during milk fermentation. The presence of these peptides is reported in various fermented milk products such as, yoghurt, cheese, sour milk, etc., which are also available as commercial products. Many of the ACE-I peptides formed during milk fermentation are resistant to gastrointestinal digestion and inhibit angiotensin converting enzyme (ACE) in the rennin angiotension system (RAS). There are various factors, which affect the formation ACE-I peptides and their ability to reach the target tissue in active form, which includes type of starters (lactic acid bacteria (LAB), yeast, etc.), substrate composition (casein type, whey protein, etc.), composition of ACE-I peptide, pre and post-fermentation treatments, and its stability during gastrointestinal digestion. The antihypertensive effect of fermented milk products has also been proved by various in vitro and in vivo (animal and human trials) experiments. This paper reviews the literature on fermented milk products as a source of ACE-I peptides and various factors affecting the production and activity of ACE-I peptides.

Co-transformation mediated stacking of blast resistance genes Pi54 and Pi54rh in rice provides broad spectrum resistance against Magnaporthe oryzae.

KEY MESSAGE: This is the first report of stacking two major blast resistance genes in blast susceptible rice variety using co-transformation method to widen the resistance spectrum against different isolates of Magnaporthe oryzae. Single resistance (R-) gene mediated approach for the management of rice blast disease has met with frequent breakdown in resistance response. Besides providing the durable resistance, gene pyramiding or stacking also imparts broad spectrum resistance against plant pathogens, including rice blast. In the present study, we stacked two R-genes; Pi54 and Pi54rh having broad spectrum resistance against multiple isolates of Magnaporthe oryzae (M. oryzae). Both Pi54 and Pi54rh expressed under independent promoters were transferred into the blast susceptible japonica rice Taipei 309 (TP309) using particle gun bombardment method. Functional complementation analysis of stacked transgenic rice lines showed higher level of resistance to a set of highly virulent M. oryzae isolates collected from different rice growing regions. qRT-PCR analysis has shown M. oryzae induced expression of both the R-genes in stacked transgenic lines. The present study also demonstrated the effectiveness of the strategy for rapid single step gene stacking using co-transformation approach to engineer durable resistance against rice blast disease and also this is the first report in which two blast R-genes are stacked together using co-transformation approach. The two-gene-stacked transgenic line developed in this study can be used further to understand the molecular aspects of defense-related pathways vis-a-vis single R-gene containing transgenic lines.

Molecular cytogenetic characterization of two Turner syndrome patients with mosaic ring X chromosome.

PURPOSE: In the present study, we reported two cases of TS with mosaic ring X chromosome showing common clinical characteristics of TS like growth retardation and ovarian dysfunction. The purpose of the present study was to cytogenetically characterize both cases. METHODS: Whole blood culture and G-banding were performed for karyotyping the cases following standard protocol. Origin of the ring chromosome and degree of mosaicism were further determined by fluorescence in situ hybridization (FISH). Breakpoints and loss of genetic material in formation of different ring X chromosomes r (X) in cases were determined with the help of cytogenetic microarray. RESULTS: Cases 1 and 2 with ring chromosome were cytogenetically characterized as 45, X [114]/46Xr (X) (p22.11q21.32) [116] and 45, X [170]/46, Xr (X) (p22.2q21.33) [92], respectively. Sizes of these ring X chromosomes were found to be ~75 and ~95 Mb in cases 1 and 2, respectively, using visual estimation as part of cytogenetic observation. In both cases, we observed breakpoints on Xq chromosome were within relatively narrow region between Xq21.33 and Xq22.1 compared to regions in previously reported cases associated with ovarian dysgenesis. CONCLUSIONS: Our observation agrees with the fact that despite of large heterogeneity, severity of the cases with intact X-inactive specific transcript (XIST) is dependent on degree of mosaicism and extent of Xq deletion having crucial genes involved directly or indirectly in various physiological involving ovarian cyclicity.

Maternal risk for down syndrome and polymorphisms in the promoter region of the DNMT3B gene: a case-control study.

BACKGROUND: Epigenetic changes leading to improper methylation of the pericentromeric region of chromosome 21 may contribute to the nondisjunction of this chromosome. Polymorphisms in the DNA Methyltransferase 3B (DNMT3B) gene, one of the crucial gene of the folate metabolism, affects the activity of the enzyme and increases the susceptibility of nondisjunction in mothers of Down syndrome children (MDS). METHODS: Considering this hypothesis we investigated the association of single nucleotide polymorphisms in the promoter region of the DNMT3B gene (rs1569686 -579G>T; rs2424913 -149C>T) with a predisposition of mothers to deliver a Down syndrome (DS) child. The study was performed on DNA samples from 150 MDS and 172 control mothers. Transmission disequilibrium tests were performed on 103 DS trio families. Genotyping was done using a polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: With respect to the single nucleotide polymorphisms studied, no significant difference was observed in the genotypes and alleles frequency distributions between MDS and control mothers. The frequency of the DNMT3B-579G allele was, respectively, 0.34 in MDS and 0.33 in control mothers whereas the frequency of the DNMT3B-149C allele was respectively 0.31 in MDS and 0.26 in control mothers. No significant deviation in genotypic combinations as well as in transmission disequilibrium tests analysis was observed. However, a strong linkage disequilibrium was observed with significant differences in the distribution of G-T and G-C haplotypes among case and control mothers. CONCLUSION: Although the above studied polymorphisms of DNMT3B may not be an independent risk factor it might be possible that certain allelic combinations (G-T) are. This finding suggests that DNMT3B might be a maternal risk factor for DS in our Indian cohort. Replication studies are required to confirm these findings.