HEALTH AND WELLNESS

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​PSBMB Scientific Posters Committee
HEALTH-01

UNDERSTANDING SURVIVAL AND DEFENSE FACTORS IN LACTOBACILLUS MUCOSAE LM1, LACTOBACILLUS PLANTARUM SK 151, LACTOBACILLUS FERMENTUM SK 152, AND LACTOBACILLUS JOHNSONII PF01 AND THEIR ROLE IN PATHOGENICITY AS IDENTIFIED THROUGH COMPARATIVE GENOMICS

Patrick Josemaria d.R Altavas, Marilen P. Balolong, Leslie Michelle M. Dalmacio, and Dae-Kyung Kang
ABSTRACT

​Microorganisms belonging to the Lactobacillus genus complex (LGC) are often used for consumption and are generally safe, but can cause infections in some rare cases, and so screening and understanding genetic factors that may contribute to pathogenicity can yield valuable insights regarding probiotic safety. The bacteria Lactobacillus mucosae LM1, Lactobacillus plantarum SK 151, Lactobacillus fermentum SK 152, andLactobacillus johnsonii PF01 are current probiotics of interest and their safety profiles have not been explored. The genome of these bacteria were downloaded from the NCBI GenBank and were annotated using Rapid Annotation using Subsystem Technology (RAST) tk pipeline and were queried using command line BLAST against the Virulence Factor Database (VFDB) and the Comprehensive Antibiotic Resistance Database (CARD) to detect potential virulence factors and antibiotic resistance (AR) genes. The genomes were then ran against ResFinder and BAGEL4 to detect acquired AR genes and bacteriocins, respectively. The query against the VFDB identified genes hasC, clpP, tufa, cpsI, msrA/B(pilB), and bsh, all of which have a role in bacterial survivability have no implication in causing damage and disease in humans and no acquired AR genes were detected using CARD and ResFinder. Although survival genes were identified based on the VFDB for the four strains, the potential for probiotic bacteremia and disease, seen in isolated and susceptible cases, is based on a complex host-microbe interaction, and may not be easily predicted using existing databases due to lack of a true pathogenic representative of common probiotic species. This study suggests that the given strains have no known virulence factors capable of producing toxins and inducing damage to the body, and that the identified genes mostly play a role in bacterial defense and survival in the human host rather than pathogenicity.

Keyword: Lactobacillus plantarum; Lactobacillus fermentum; Lactobacillus mucosae, Lactobacillus johnsonii; Comparative Genomics; Probiotics
HEALTH-02

IN VITRO ANTIMICROBIAL AND ANTIBIOFILM PROPERTIES OF ENGINEERED HISTATIN 8 (HS8) PEPTIDES AGAINST Pseudomonas aeruginosa

Nedrick T. Distor and Leslie Michelle M. Dalmacio
ABSTRACT

​The heightened, unregulated use of antibiotics have led to the emergence and rapid spread of antimicrobial resistance (AMR) as a global clinical crisis. In the Philippines, antibiotic-resistant Pseudomonas aeruginosa are reported and associated to nosocomial and human gut-related infections. As alternatives to antibiotics, antimicrobial peptides (AMPs) are promising molecules to study having unique bioactivities. The 12-amino acid peptide named histatin 8 (HS8) is an AMP candidate for engineering studies to significantly improve their biofunctional property and safety. The general objective of the study is to determine the effect of amino acid (X) substitution on the antimicrobial, antibiofilm, and hemolytic properties of HS8 against non-resistant P. aeruginosa. In silico development and prediction revealed three potent peptides namely HS8-1 (Tyr12→X12 substitution), HS8-2 (Ser8→X8 and Tyr12→X12 substitutions), and HS8-3 (Gly11→X11 substitution). In vitro antimicrobial assay through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determinations of the first two peptides revealed that HS8-1 (MIC = 270.83 μg/mL; MBC = 140.63 μg/mL) is a more potent antimicrobial peptide compared to HS8 (MIC = 805.56 μg/mL; MBC = 500 μg/mL), HS8-2 (MIC = 354.17 μg/mL; MBC = 250 μg/mL), and HS8-3 (MIC = 562.50 μg/mL; MBC = 250 μg/mL). Antibiofilm assays through minimum biofilm inhibitory concentration (MBIC) determinations revealed that HS8-2 (MBIC = 15.63 μg/mL) is a more potent antibiofilm peptide compared to HS8-1 (MBIC = 125 μg/mL). The hemolytic activities of the peptides were also assessed. Results suggest that the observed antimicrobial and antibiofilm property improvements were achieved by performing specific amino acid substitution(s) in the peptide at specified positions. Further works will focus on exploring the effect of the peptide analogs against antibiotic-resistant P. aeruginosa and the possible morphological changes in the P. aeruginosa membrane to completely assess the antimicrobial properties of peptides.

Keyword: antimicrobial resistance, Pseudomonas aeruginosa, antimicrobial peptides, peptide engineerin
HEALTH-03

PROBING THE ROLE OF DIFFERENT MEMBRANE REPAIR MECHANISMS DURING NECROPTOTIC CELL DEATH

Rafael A. Espiritu, Uris Ros, Ana J. Garcia-Saez
ABSTRACT

​Necroptosis is a caspase-independent form of regulated cell death involved in numerous pathophysiological conditions. This mechanism of cell death is inherently immunogenic due to the release of damage-associated molecular patterns upon plasma membrane rupture. During the execution of necroptosis, the cell activates various counterbalancing repair mechanisms that serve to delay cell death and allow proper cell-to-cell communication to occur. Here, we show that CHMP4B, an ESCRT-III component previously implicated in membrane repair, is activated, and forms punctae concomitant with an increase in cytosolic Ca2+ concentration. Previous data showed that damaged membranes were shed during necroptosis, which we similarly observed but only in a very small proportion of cells. Instead, most of the CHMP4B punctae appeared intracellular in nature, suggesting the possible involvement of other pathways in membrane repair. Shedding light on how these repair mechanisms work during necroptosis will be important towards understanding the potential means by which we can control this type of cell death, and possibly exploit it for some therapeutic benefit.

Keyword: necroptosis, ESCRT-III, CHMP4B, plasma membrane repair
HEALTH-04

EFFECT OF LACTIC ACID BACTERIA SUPPLEMENTATION ON LIFESPAN, SOMATIC MAINTENANCE AND STRESS RESISTANCE IN CAENORHABDITIS ELEGANS

Ryan C.V. Lintao and Paul Mark B. Medina
ABSTRACT

​Probiotics have long been associated with enhanced longevity and health-promoting effects on the host, however the recent discovery of microbiota-gut-brain axis as an important mediator of stress response has allowed us to make the connection between microbiota, stress, and aging. We looked at the effect of lactic acid bacteria (LAB) on lifespan and healthspan using  Caenorhabditis elegans, a widely accepted animal model for host-microbe interactions. The E. coliOP50 diet of C. elegans was supplemented with one of four Lactobacillus species (L. acidophilus, L. bulgaricus, L. casei, and L. paracasei), and was given to L4-stage worms. Lifespan parameters were determined, and indicators of healthspan such as locomotion, fecundity, and resistance to heat and oxidative stresses  were measured. These parameters were compared between treatment groups (i.e., LAB-supplemented OP50 diet) and the control group (i.e., OP50-only diet). Among the four LAB, only L. acidophilus significantly increased the lifespan of C. elegans when supplemented in the diet. Supplementation with either of the four LAB significantly improved survival of C. elegansbeyond its mean lifespan, without any significant inhibitory effect on locomotion and fecundity. Under chronic heat stress and oxidative stress, LAB supplementation also significantly improved survival in spite of having shorter mean lifespan compared to C. elegans not exposed to either stresses. Overall, L. acidophilus exhibited the greatest increase in lifespan and in healthspan. These findings add to the growing evidence regarding the contribution of probiotic supplementation to decreased risk of age-related morbidities.

Keyword: probiotics; Lactobacillus spp.; survival; healthspan; Caenorhabditis elegans
HEALTH-05

ANTIBACTERIAL POTENTIAL OF LOCALLY FORMULATED DISINFECTANT/ANTISEPTIC FROM NIPA BIOETHANOL

James Paul T. Madigal, Thiara Celine E. Suarez, Karyl Mae D. Ramos, Jayson F. Cariaga and Shirley C. Agrupis
ABSTRACT

​Ethyl Alcohol, 70% was formulated from Nipa Bioethanol, “Nipahol”, to augment the dwindling supply of alcohol to fight COVID-19. Nipahol is a high-grade bioethanol produced from nipa sap using the proprietary fermentation and distillation technologies developed by a group of researchers at the MMSU-NBERIC. For more than a decade now, MMSU has been implementing RDE for the production of fuel-grade ethanol from non-traditional sugar feedstocks like nipa sap in support of the Biofuel Act of 2006. To ensure the quality and efficacy of the formulated product, the present study was set to explore the antibacterial potential of the locally formulated nipa disinfectant/antiseptic as an alternative alcohol formulation amid COVID-19 pandemic using standard microbiological assays. Susceptibility test revealed that 70% and 80% nipa alcohol formulations showed inhibitory activity against Staphylococcus aureus (6.25 mm and 4.25 mm zone of inhibitions). The 95% nipa alcohol concentration showed bactericidal effect against Escherichia coli and S. aureus. High percent (%) bacterial cell reduction (90-99.9% log reduction) was observed when alcohol concentration and time increases. Confirmatory antimicrobial susceptibility test conducted by DOST-RO1 Microbiology Division reported that 95% nipa alcohol showed active inhibitory effect to test organisms while partial active observed in 70% nipa alcohol formulation. Glo-Germ Test revealed nipa disinfectant/antiseptic is as effective as the commercial alcohol, thus, it can be utilized as an alternative intervention to prevent the spread of infectious microorganisms. The effectiveness of nipa disinfectant/antiseptic formulations is heightened with proper hand washing, strictly following proper hygiene, and health protocols. In conclusion, the formulated nipa disinfectant/antiseptic possesses antibacterial potential to inhibit the multiplication of E. coli and S. aureus.

Keyword: nipa bioethanol, nipa disinfectant/antiseptic, percent bacterial cell reduction, antimicrobial susceptibility, Glo germ test
HEALTH-06

ACTIVITY OF PUTATIVE BACTERIOCINS FROM LACTOBACILLUS PLANTARUM BS25 AND PEDIOCOCCUS ACIDILACTICI S3 AGAINST ANTIBIOTIC-RESISTANT VIBRIO SPP.

Joshua Angelo H. Mandanas, Leslie Michelle M. Dalmacio, Marilen P. Balolong
ABSTRACT

​Vibrio spp. with antibiotic resistance phenotypes were previously isolated from Manila Bay and is considered a possible threat to public health. Lactic acid bacteria (LAB), the commonly used microorganisms in food fermentation and a natural, sustainable flavour enhancer, secrete metabolites that have antimicrobial activities. It is then worth exploring the potential of these metabolites against pathogens from environmental reservoirs. This study determined the inhibitory effects of crude cell free supernatant (CFS) and ammonium sulfate precipitate (ASP) preparations from Lactobacillus plantarum BS25 (LP) and Pediococcus acidilactici S3 (PA) against antibiotic-resistant Vibrio alginolyticus(P3) and Vibrio fluvialis (0405-W4-01-02) isolates. Resazurin assay showed that CFS and ASP from LP and PA can inhibit antibiotic resistant strains of Vibrio spp. isolates with highest recorded activity against Vibrio fluvialis. Preparations of putative bacteriocins of 123 mg/mL from 1.94 x 10¹² CFU/mL PA (CFS) exhibited 92% inhibition while 86 mg/mL from 1.703 x 10¹² CFU/mL LP (ASP) showed 99% inhibition against 1.87 x 10¹² CFU/mL of Vibrio fluvialis (50 uL and 40uL, respectively). The activities observed were higher compared to the control (225 ppm) tetracycline by 6% and 29% (a=0.05, p < 0.00001), respectively. Total protein content from ASP preparation of LP (0.012 mg/mL) and PA (0.016 mg/mL) were determined using Bradford assay. Putative class I and III bacteriocins were observed in SDS-PAGE bands of LP (10kDa, 37kDA to 75 kDa) and PA (10kDa, 37 to 100kDa), respectively. Putative bacteriocins from LP and PA have inhibitory effects against antibiotic-resistant Vibrio spp. Results of the study can be used in the development of postbiotics against antibiotic-resistant pathogens isolated from environmental reservoirs.

Keyword: LAB, Lactobacillus plantarum BS25, Pediococcus acidilactici S3, Vibrio spp., Postbiotics
HEALTH-07

ANTICANCER POTENTIAL OF ELEUSINE INDICA METHANOLIC LEAF EXTRACT VIA RAS- AND WNT-RELATED PATHWAYS EVALUATED IN TRANSGENIC CAENORHABDITIS ELEGANS STRAINS

John Sylvester B. Nas, Sheryl E. Dangeros, Princess Dianne R. Chen, Rosemarie C. Dimapilis, Daniel Joshua G. Gonzales, Fatima Jeda A. Hamja, Cathdrin Joyce Ramos, Ashera D. Villanueva
ABSTRACT

​In the Philippines, many accounts have resurfaced claiming different herbal and therapeutic advantages of Eleusine indica (Indian goosegrass), such as antiviral, anti-plasmodial, antidiabetic, antioxidant, antidiuretic, anti-inflammatory, and antibacterial properties [1-3]. One of these advantages is its anticancer potential. Despite some studies claiming that the crude extract has cytotoxic and pro-apoptotic activity, it is still insufficient [4-5]. Hence, further scientific evidence is needed to support this claim. In this study, we evaluated the anticancer potential of E. indica methanolic leaf extract (EMLE) by focusing on two cancer-related pathways, Ras and Wnt pathways. Dysregulation in the Wnt pathway has been linked to colorectal cancer, ovarian cancer, and breast cancer. Meanwhile, irregularities in the Ras pathway are associated with myelomonocytic leukemia, ovarian cancer, colorectal cancer, and cervical cancer. We used wild-type and transgenic Caenorhabditis elegans strains, which have irregular Ras or Wnt signaling. Humans and C. elegans share comparable Ras and Wnt signaling pathways, especially their downstream targets. We determined the average number of eggs laid of each strain and the multi-vulva development of the Ras-mutant strain. Our findings show that EMLE does not affect the number of eggs laid of the wild‐type, Ras‐mutant, and Wnt‐mutant worms. Furthermore, EMLE was not able to reduce the Ras-mutant population demonstrating multi-vulva. Taken together, our data suggest that the anticancer potential of EMLE may be independent of Ras and Wnt signaling pathways.

Keyword: Anticancer, Eleusine indica, Ras pathway, Wnt pathwa
HEALTH-08

ANTIBACTERIAL EFFECT OF VERNONIA CINEREA ROOT EXTRACT COMPARED WITH MUPIROCIN AGAINST Staphylococcus aureus- INDUCED WOUND IN MICE

Zyrhine Kaye Paiso
ABSTRACT

​Wounds, if not properly managed, become one of the leading causes of morbidity and mortality in the country. That being said, the use of herbal drugs to explicate their potential in wound management and as natural remedies is growing due to its cheaper price and greater accessibility. Vernonia cinerea, also known as Tagulinaw, is a potential medicinal plant. The study aims to determine the antibacterial effect of Vernonia cinerea root extract against Staphylococcus aureus -induced wound in mice. Vernonia cinerea dried roots were pulverized and the extract was made into an ointment. The study lasted for 16 days and applications of Mupirocin (positive control), Paraffin base (negative control) and Vernonia cinerea ointment were done once a day. The percent wound reduction in size was measured using a ruler and bacterial colony count was done. Results revealed that the Mupirocin and Vernonia cinerea ointment were comparable in eradicating Staphylococcus aureus on the wound of the mice based on the colony count done between the groups. On the other hand, the percent of wound reduction in size increases from the first day (4th) of measurement till the last day (16th) of observation. It was concluded that Vernonia cinerea ointment was effective in healing wounds and in the prevention of bacterial infections.

Keyword: Mupirocin, Staphylococcus aureus, Tagulinaw, Vernonia cinerea
HEALTH-09

IMMUNOMODULATORY POTENTIAL OF FOUR PROBIOTIC LACTOBACILLUS STRAINS FROM PLANT AND ANIMAL ORIGIN USING COMPARATIVE GENOMIC ANALYSIS

Paul Benedic U. Salvador, Marilen P. Balolong, Leslie Michelle M. Dalmacio, and Dae-Kyung Kang
ABSTRACT

​Probiotics strains from different origins have shown promise in recent decades for its health benefits such in promoting and regulating the immune system. Immunomodulatory potential of four probiotic Lactobacillus strains from animal and plant origins was evaluated in this paper based on their genomic information. Comparative genomic analysis was performed through genome alignment, average nucleotide identity (ANI) analysis, and gene mining for putative immunomodulatory genes. Genomes of the four probiotic strains show relative similarities in multiple regions as observed in the genome alignment. However, ANI analysis showed that L. mucosae LM1 and L. fermentum SK152 are the most similar when considering their nucleotide sequences alone. Gene mining of putative immunomodulatory genes studied from L. plantarum WCFS1 yielded multiple results in the four probiotic species with L. plantarum SK151 showing the most number of genes at around 74 hits followed by L. johnsonii PF01 at 41 genes when adjusted for matches with at least 30% identity. Looking at the immunomodulatory genes in each strain, L. plantarum SK151 and L. johnsonii PF01 may have wider activity, covering both immune activation and immune suppression, as compared to L. mucosae LM1 and L. fermentum SK152 which could be more effective in activating immune cells and the pro-inflammatory cascade rather than suppressing it. Similarities and differences in the four Lactobacillus species showed that there is no definitive trend based on the origin of isolation alone. Moreover, higher percent identities between genomes do not directly correlate to higher similarities in its potential activity such as in immunomodulation. Immunomodulatory function of each of the four Lactobacillus strains should be observed and verified experimentally in the future since some the activity of some genes may be strain-specific which would not be identified through comparative genomics alone.
HEALTH-10

CTTNBP2 AND ZINC, AS BROTHERS IN ARMS IN AUTISM SPECTRUM DISORDER

Pu-Yun Shih and Yi-Ping Hsueh
ABSTRACT

​Autism spectrum disorder (ASD) is a highly prevalent psychiatric disorder. Both genetic and environment factors are involved in ASD etiology. Recently we reported the molecular and physiological role of an ASD high risk gene, Cortactin-binding protein 2 (CTTNBP2) from mouse genetic models. We showed that Cttnbp2deficiency leads to aberrant social interaction, one of the core symptoms of ASD. Proteomic and immunoblotting analyses further revealed that a set of ASD-associated genes, including SHANKs and NMDAR, are down-regulated in Cttnbp2 deficiency synaptosomal fraction. Administration of D-cycloserine (DCS, a NMDAR coagonist) improves social behavior defects of CTTNBP2 deficiency models further validates the involvement of NMDAR signaling in CTTNBP2 regulated social behaviors. In addition, zinc association is also one of the convergent features in differentially expressed proteins identified in Cttnbp2 deficient synaptosomal fractions. The concentration of zinc in Cttnbp2 deficient brain tissue is also reduced. Seven days of zinc supplementation improved social behaviors of Cttnbp2 deficient models. These results suggest, as a genetic factor, Cttnbp2 interacts with zinc, an environmental factor in regulation of social behaviors. Our model provides an example of genetic and environmental factor interaction in ASD etiology. 
HEALTH-11

DIET COMPOSITION AND GUT MICROBIOME OF HEALTHY ADULTS
​ IN ALBAY AND MANILA

Abraham C. Sianoya, Leslie Michelle M. Dalmacio PhD, Jiro Nakayama PhD
ABSTRACT

​Gut microbes interact with their host in maintaining health or in the development of disease. Of the many factors that affect its structure, diet is one that can be classified by geographic location (rural vs. urban). Since health and disease also varies across locations, the study of gut microbiota, as an interface between diet and health status, can provide insights to the understanding of disease states. Therefore, this study will determine differences in the diet and the gut microbiome of healthy adults from rural Albay and urban Manila. A total of 61 healthy adult participants was recruited: 37 from Albay and 24 from Manila, with the given number of participants per group allowing ≥90% power to detect an effect size less than the set type I error (a=0.05). Their demographic profile, dietary information, and stool samples were collected. Fecal bacterial DNA was extracted from the stools and the 16 rRNA gene was sequenced on MiSeq. The gut microbiome profile was determined using QIIME/USEARCH. Based on the dietary information, Albay has significantly higher consumption of rice and porridge and carbohydrates intake than Manila (p<0.05) while protein and fat intake are the same between groups. Based on the sequencing data to date, Manila has significantly higher abundance of Bifidobacteriaceae (p<0.05), a driver of BB-type microbiota expected in a high-fat, high-protein diet. The Prevotella abundance that is associated with vegetarian and high-plant-polysaccharide diets was inversely proportional to Bacteroides abundance, another driver of the BB-type microbiota. Lastly, gut bacterial diversity represented by the number of detected OTUs per sample in Albay is significantly greater than that of Manila (p<0.05). This shows that the abundance of certain bacterial signatures such as Bifidobacteriaceae and Prevotella and gut bacterial diversity vary between urban and rural healthy adult individuals who consume different diets.
HEALTH-12

NEUROPROTECTIVE EFFECTS OF THE OXINDOLE ALKALOIDS ISOMITRAPHYLLINE AND MITRAPHYLLINE IN DAMAGED HUMAN NEUROBLASTOMA SH-SY5Y CELLS

Mario A. Tan and Seong Soo A. An
ABSTRACT

​Alzheimer’s disease (AD) is a dominant neurological disorder characterized by cognitive impairments and synaptic dysfunctions affecting mostly the elderlies. There are only five drugs approved to minimize the progression of symptoms related to AD. Hence, the challenge of finding an alternative treatment or therapy from natural products is warranted. The purified oxindole alkaloids, isomitraphylline and mitraphylline from Uncaria perrottetii (locally known as “sungay kalabaw”), revealed their ability to break amyloid aggregates in vitro suggesting their therapeutic potentials in Alzheimer’s disease (AD). Thioflavin-T assay for assessing amyloid-beta (Ab) aggregation of these alkaloids exhibited inhibitions at 60.32% ± 2.61 (50 mM) for isomitraphylline and 43.17% ± 3.48 (50 mM) for mitraphylline. Neuroprotective effects were elaborated against Ab-induced SH-SY5Y cells at 20 mM and 10 mM for isomitraphylline, and 20 mM for mitraphylline. In addition, both alkaloids attenuated and protected the H2O2-induced SH-SY5Y cell cytotoxicity at 20 mM. The intracellular ROS levels of SH-SY5Y cells from H2O2-induced oxidative stress were reduced at 20 mM and 10 mM, and the mitochondrial membrane potentials of Ab-induced SH-SY5Y cells were protected at 20 mM. The overall results suggested the potentials of both alkaloids to target certain pathological biomarkers of AD and could be further investigated as therapeutic or preventive drug leads against AD.

Keywords: Alzheimer’s disease; Oxindole Alkaloids; SH-SY5Y cells; Uncaria perrottetii
HEALTH-13

PREVALENCE OF PKS+ ESCHERICHIA COLI IN COLORECTAL CANCER AMONG SELECTED FILIPINO CASES

Carmina V. Tolentino, Ma. Kristina Carmela Aguilar, Ana Maria Cariño, Allan Fellizar, Antonio Lim, Lara Angeles,
​ Lorenzo Abanilla, David Angelo Guanzon, and Pia Marie Albano
ABSTRACT

​Colorectal cancer (CRC) ranked 4th cause of cancer-related death in the world and 3rd leading cause of malignancy in the Philippines in 2018. Among the established risk factors are advancing age, family history of cancer, high fat diet, sedentary lifestyle, smoking, and alcohol. Over the past few years, there has been a growing interest on the role of the members of the gut microbiota, including Escherichia coli, in colorectal cancer development. Some E. coli strains may carry the pks pathogenicity island, which encodes the compound colibactin that is believed to alkylate DNA on adenine residues and induce double-strand break. Thus, this study aimed to determine the possible association of pks+ E. coli with CRC development among selected Filipino cases. A total of 62 formalin fixed paraffin embedded (FFPE) colorectal tissues positive for cancer cells (cases) matched with 62 cancer-free tissues (controls) were analyzed for presence of uidA, clbB, clbN and clbA genes using an in-house developed realtime qPCR. Results show that there is no significant difference (p˃0.05) between the cases and controls in terms of prevalence of the uidAgene, which is an important target for the detection of E. coli. As to the markers of the pks pathogenicity island, clbNgene was more prevalent (p<0.05) in cancer-free tissues than in malignant colorectal samples. No significant difference (p˃0.05) was observed between cases and controls in terms of prevalence of the clbA and clbB genes. Therefore, pks+ E. coli may not be a risk factor in CRC development among Filipinos.

Keywords: colorectal cancer, pks+ Escherichia coli, realtime qPCR, formalin fixed paraffin embedded (FFPE) colorectal tissues, gut microbiot
HEALTH-14

ASSESSMENT OF THE PREBIOTIC ACTIVITY OF ARABINOGALACTANS ISOLATED FROM ZEA MAYS ON BACTEROIDES ACIDIFACIENS AND SECRETORY IGA LEVELS IN BALB/C MICE

Francis Jayson B. Vallesfin and Leslie Michelle M. Dalmacio
ABSTRACT

​Introduction: Arabinogalactan is a prebiotic  that can be extracted from Larch tree, carrots, wheat and corn. Various clinical studies associated arabinogalactan supplementation to increased immune defenses. Bacteroides acidifaciens, a resident microflora of both mouse and human colon, has been demonstrated to induce sIgA levels and promote B cells in colon of gnotobiotic mice. Larch arabinogalactans and B. acidifaciens had been separately shown to increase sIgA expression levels. However, there is no study that correlates the increase in sIgA levels with the increase in B. acidifaciens population due to a prebiotic.

Objectives: The study aims to utilize corn as alternative source of arabinogalactans since Larch tree is not easily grown in tropical countries. The effect of corn (Zea mays) arabinogalactans on B. acidifaciens is being investigated to support the sIgA immune response.

Major Findings: Arabinogalactans were extracted from fresh corn kernels. The growth curve of B. acidifaciens reference culture on culture media containing various arabinogalactan concentrations were used to determine the optimum prebiotic dosage. The prebiotic activity of corn (Zea mays) arabinogalactan granules on Bacteroides acidifaciens was determined in vitro using batch culture fermentation.  It was found that the optimum prebiotic dosage is 1.0 mg/mL. Using Eggert-Gangnon broth, enrichment with Larch  and corn arabinogalactan showed bacterial growth of 6500 ± 80 cells and 7200 ± 150 cells, respectively, as compared to 3000 ± 90 cells of the negative control and 4800 ± 200 of the inulin treatment (positive control) after 6 hours of fermentation. In an in vitro set-up, it is observed that corn arabinogalactan enrichment can reach a maximum prebiotic score of 2.2 . Preliminary study of BALB/c mice treatment with corn arabinogalactan indicates an increase in total protein content  in the fecal samples. QPCR analysis of fecal DNA sample from mice treatment showed an increase in B. acidifaciens population after 30 days of supplementation with 0.1 mL 1.0 g/mL corn arabinogalactan treatment. 

Conclusion: The data from batch culture fermentation suggests that medium enrichment with arabinogalactan has a positive effect to the population growth of B. acidifaciens. The maximum prebiotic score of 2.2 implicates that B. acidifaciens has enzymes that can utilize arabinogalactan which results to an increase in growth rate. The increase in totat protein content may indicate an increase in sIgA expresson; to confirm this hypothesis, an sIgA ELISA is needed. In the next step of the study, in vivo prebiotic activity of corn arabinogalactan and the mucosal sIgA expression levels from fecal and colon swab samples collected will be compared among different treatment groups of BALB/c mice.

Keywords: Zea mays, Bacteroides acidifaciens, prebiotics, sIgA immune response, arabinogalactans