Module 3: Lesson 11 – Panel Discussions (Nutrigenomics & Microbiomes)

Please note that this Lesson has two parts a) Nutrigenomics b) Microbiomes.

Part A: The gastrointestinal microbiome
Dr Mamadou Kaba
Senior Researcher in the Division of Medical Microbiology. My research interest is the study of the microbiome in healthy and diseased conditions.

Name: Tracy Meiring Affiliation: University of Cape Town
Location: Cape Town, South Africa

Dr Meiring is a geneticist whose research interests include the genital microbiome and its associations with human immunodeficiency virus (HIV) and human papillomavirus (HPV) infection. She is interested in the application of next generation sequencing technologies to detect and quantify the bacteria and viruses in genital niches. Dr Meiring is a lecturer in the Division of Medical Virology, University of Cape Town. In 2014 she was awarded a NRF Research Career Advancement Award.

This topic aims to provide participants with a basic understanding of the gut microbiome through a panel discussion, where the microbiome originates, how it is studied and how it develops through life and its potential role in health and disease conditions. The emphasis will be on the gut microbiome.

Learning Outcomes
On completion of this module the participants will be able to:
● Define the microbiome
● Describe the methods used to analyse the microbiome
● Describe the basic characteristics of the gut microbiome and how it develops
● Summarise a few examples of how the gut microbiome may impact health and disease
● List potential interventions for gut microbial imbalances or dysbiosis

Class Videos

Class Slides

Assessments: Pre-Class Exercise
Click to read: Probiotics found in yoghurt can reverse depression symptoms?
Click to access: Gut Microbiomes of Malawian Twin Pairs Discordant for Kwashiorkor. Smith et al. 2013.
1) Every person carries bacteria. Do you think both environmental and genetic factors could
influence the composition of someone bacteria in their stomach?
2) Why are antibiotics normally given in combination with probiotics?

Assessments: Class Exercise
Millions of children worldwide suffer from severe acute malnutrition (SAM). Kwashiokor is the form of SAM characterised by generalised oedema, fatty liver, anorexia, skin rashes and ulcerations. The cause of kwashiorkor is not known. International guidelines now recommend the use of ready-to-use therapeutic food (RUTF) — usually a fortified spread consisting of peanut paste, milk powder, oil, sugar, and a micronutrient supplement — in outpatient settings as the preferred management for uncomplicated cases of severe acute malnutrition. This revised outpatient regimen has had markedly better outcomes than inpatient treatment with fortified milk formulae BUT 10 to 15% of children still do not recover. In the Smith et al. 2013 paper, “Gut microbiomes of Malawian twin pairs discordant for kwashiorkor”, the authors ask the question: Is the gut microbiome involved in kwashiorkor?
The first part of the study examined the gut microbiomes of 317 Malawian twins over a 3 year period. Over the course of the study 50% of the twin pairs remained well nourished, 43% became discordant and 7% concordant for acute malnutrition. Comparing the gut microbiomes of twin pairs discordant for kwashiorkor revealed that the gut microbiome of the co-twin with kwashiorkor did not mature and had lower gene content. When the children were fed RUTF, there was transient maturation of the gut microbiome in the kwashiorkor co-twins, but this regressed once RUTF treatment was halted.

Question: Part A
1. What was the benefit of using twin pairs in this study?
Read the section of the Gut Microbiomes of Malawian Twin Pairs Discordant for Kwashiorkor. Smith et al. 2013. article which is titled “Transplantation of fecal communities into gnobiotic mice” (page 550) and answer the following:

Questions: Part B
2. Why did they use gnobiotic (germ-free) mice?
3. What happened to the weight and gut microbiota of the mice that received fecal transplants from the co-twin with kwashiokor and Malawian diet? What happened when the diet was changed to RUTF?
4. What are the limitations of the experiment?

Open class discussion:
Do you think microbial-based interventions may in the future be used to improve outcomes in malnutrition? What types of interventions are possible?
Class Evaluation
See course evaluations section.

Part 2: Nutrigenomics

Name: Prof Samar Kassim
Affiliation: Faculty of Medicine, Ain Shams University,
Location: Cairo, Egypt

Upon completion of her doctorate in Medical Biochemistry & Molecular Biology, thesis titled “Biochemical Studies Based on Signal Transduction by C-erbB-2 gene Product”, Duke University Medical Center, Durham, NC, she published many articles in the area of cancer diagnosis (Mansour et al, 2012, Eissa et al, 2011, Eissa et al, 2005, Kassim et al, 2004, etc.) where she helped establishing detection systems for many epithelial tumors. At 2002, she joined Glasgow Caledonian University where she identified the differences between breast and ovarian cancers in the Androgen receptor gene methylation and exon one CAG repeat length (Kassim et al, 2004). She joined important research in the molecular events accompanying hepatitis C viral infections among Egyptian patients (Hassan et al, 2007, and Hassan et al, 2002). Dr. Kassim published a large longitudinal study in the American Journal of Gastroenterology about the Host and viral determinants of the outcome of exposure to HCV infection genotype 4 (Kamal et al, 2014). She shared the development of Bioinformatics Master and undergraduate programs in Helwan and Ain Shams Universities. She is the Co-PI of the Egyptian node of H3ABioNet Pan-African Network
This session will highlight the importance of incorporating genetics into the field of nutrition (explains how our diet interacts with our genes). Nutrigenomics asks how dietary components influence gene expression, while Nutrigenetics asks how our genetic makeup makes us respond or not to different types of food. Some examples of diet-gene interactions will be demonstrated with focus on how this interaction plays a significant role in the between-person variability and how this can lead to the development of personalized nutrition.

Learning Outcomes
● Define nutritional Genomics and its two disciplines: nutrigenomics and nutrigenetics,
● Describe how nutrients could affect health.
● Summarise a few examples of nutrients that can influence gene expression.
● Describe how nutritional management can modify some genetic diseases.

Assessments: Pre-Class Exercise
Question 1: Read the article below:
Genetic Tests Solve Diet Riddles
Any thoughts or reflections?

Question 2: What is gene expression?
Extra Reading (Credit Health24).
Nutritional genomics and personalized diet – article

Class Videos

Class Slides

Assessments: Class Exercise
Question 1: Mamadu and Amadu are identical twins who grew up together but have lived apart since college. Mamadu stayed city they were born in and studied in accounting. He is now a certified public accountant in a bank. He is working long hours in a stressful environment. Amadu went to another school, where he studied Nutrition and Exercise Physiology and now manages a large fitness center. At age 30 the two brothers are noticeably different in weight and body shape. Mamadu has a BMI of 34 and has developed central obesity, hypertension, and problems with blood sugar control, all signs of a tendency of developing type 2 diabetes. Amadu is lean and has a normal blood pressure and normal blood sugar regulation.
Nutrition Diagnosis: Overweight/obesity in Mamadu related to possible genetic susceptibility, overeating with snacks and consumption of large meals as evidenced by central obesity and body mass index of 34.

1. Because they are identical twins, would you have expected the two brothers to have similar health profiles?
2. How would you expect their diets to be different?
3. What is going on? Does Amadu have the same genetic susceptibilities that Mamadu has? Justify your answer. If yes, why doesn’t Amadu exhibit the same phenotype as Mamadu?
4. What would you advise Mamadu to do to decrease his genetic susceptibility to diabetes?

Class Evaluation
See course evaluations section.

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