The document discusses the relationship between gut microbiome and obesity. It notes that obese individuals have different gut microbe compositions than lean individuals, with more obesity-linked bacteria like Firmicutes and less of the protective Bacteroidetes. Transplanting gut microbes from obese mice into thin mice causes weight gain. Modulating the gut microbiome through prebiotics, probiotics, synbiotics or fecal transplants may help treat and prevent obesity. The human microbiome market is growing due to increasing lifestyle diseases.

1. M I C RO B I O M E
A N D
O B E S I T Y

2. INTRODUCTION
• 10-100 trillion microorganisms reside in the gut
• Gut microbiota in germ-free mice:
– encodes metabolic capacities for degradation of indigestible components of diet
– assist in absorption of minerals and electrolytes
– catabolism of toxic carcinogens
– synthesis of micronutrients
– affects bile acid diversity
– Influences kidney homeostasis
• Microbiome varies between individuals leading to differences in ability to extract energy and
deposit as fat(lean/obese)
• Transplantation of intestinal microbes from obese individuals increased adiposity in recipients
than from lean donors

3. MICROBES INVOLVED IN OBESITY
• Obesity is highly heritable, and it probably involves genes that pass from parent to child. And
body weight is clearly influenced by diet, so the environment and personal habits also play a role
•Thin people and obese people tend to have different types of microbes living in their guts. And
when obese people lose weight, their microbiota change accordingly.(ruminococcus,halomonas
etc..)
•A diet high in fat, sugar, and simple carbs is bad for the "healthy" gut microbes that keep us thin
while it encourages the growth of "unhealthy" microbes that make us obese

4. CONT.
•Obese individuals harbor microbes that are better at extracting energy from food, as well as
microbes that signal the body to store energy as fat
•Bacteria transplanted from overweight mice to thin mice make the thin mice gain weight
•The relationship among genetics, the environment, and the microbiome as it relates to obesity is
certainly complex. But while the genome is fixed and habits are hard to change, the microbiome is
changeable

5. ROLE OF MICROBES IN OBESITY
• Many plant polysaccharides and complex carbohydrates are metabolized by the gut microbes and
convert them to short chain fatty acids (SCFA)
• Link between obesity and gut microbiota was initially studied in germ-free mice
• Conventionally reared mice have a 40% higher body fat content and 47% higher gonadal fat content,
then germ-free mice
• When the distal gut microbiota from normal mice was transplanted to gnotobiotic mice showed 60%
increase in body fat within 2 weeks
• Body fat was increased, without any increase in food consumption or obvious differences in energy
expenditure
• This showed that gut microbiota affects phenotypic characteristics related to obesity of the host

6. HUMAN STUDIES
• The association between the gut microbe and obesity has also been observed in humans
• Obese human, have low fecal bacterial diversity associated with
– Adiposity
– Dyslipidemia
– Impaired glucose homeostasis
– Higher low- grade inflammation
• Investigators used genetic sequencing of fecal samples to identify the gut microbiota of 12 obese
individuals and compared them with 5 lean volunteer
• Obese individuals had more Firmicutes and nearly 90% less Bacteroidetes than the lean individuals

7. CONT.
• In another study, variations in the fecal microbiota of 12 lean and 9 obese individuals was observed
• diets that varied in caloric content showed that an altered nutrient load, induced rapid changes in gut
bacterial community
• Higher caloric intake was associated with a 20% growth of Firmicutes and a 20% reduction in
Bacteroidetes, which was directly related to the gain in body weight
• These results suggest that differences in the microbiota precede obesity

8. OBESITY TREATMENT BY GUT
MICROBIOTA MODULATION
• Targeting microbiota may present new avenues for therapeutic interventions aimed at preventing or treating
obesity and associated metabolic disorders. These strategies included dietary manipulation by using:
1.) Prebiotics.
2.) Probiotics.
3.) Synbiotics.
4.) Transplantation of fecal microbial communities.

9. PREBIOTICS
• Can’t be digested by the host.
• Benefits the host because of the selective stimulation of growth and/or activity of the gut microbiota,
particularly lactobacilli and bifidobacteria.
• In principle, all dietary fibers that are fermented are assumed to have prebiotic properties.
• Inulin-like prebiotic fiber was associated with a significant decrease in hunger, and significantly greater
satiation after a meal and increased plasma level of glucagon-like-peptide-1 (GLP-1).

10. PROBIOTICS
• “live microoganisms which when administered in adequate
amounts, confer a health benefit on the host.”
• Probiotic carrying food: Refer to picture.
• The main probiotic supplements on the market utilize
lactobacilli, streptococci and bifidobacteria, which are
normal constituents of the human gastrointestinal
microflora.
• Lactobacillus gasseri SBT2055 (LG2055) lead to a significant
reduction in abdominal visceral fat area (8.5% decrease,
p<0.01).
• Lactobacillus rhamnosus may prevent excessive weight gain.

11. SYNBIOTIC
• Synbiotics = Prebiotics + Probiotics
• Synbiotics had been proposed to be more effective than
prebiotics or probiotics in modulating the gut microflora.
• Combination of a specific oligofructose-enriched inulin
(Prebiotics) and Lactobacillus rhammnosus GG and
Bifdobacterium lactis Bb12 (Probiotics) for 12 weeks caused a
16% and 18% increase in the numbers of Lactobacillus and
Bifidobacterium, respectively, and a 31% decrease in the
numbers of Clostridium perfringens.

12. FECAL MICROBIAL TRANSPLANT
• A.K.A stool transplant, transplantation of fecal
bacteria from a healthy individual into a
recipient to restore healthy colonic microflora
of the recipient.
• Efficacious treatment for patients with
Clostridium difficile infections but their
benefits for other conditions are less well
studied.

13. FUTURE DIRECTIONS
• According to the recent report published in ‘Research and markets’, Dublin
(GLOBE NEWSWIRE , April 2019)
• Global human microbiome market is expected to increase 22.60% in the year 2024
• Increase in lifestyle-related diseases and geriatric population
• Microbiome in new-borns' stool can predict overweight at age 3 years ,Finland
(European congress of clinical microbiology and infectious disease, April 2019)
• First-pass meconium of new borns and the stool of 1 year babies were collected
• Relative abundance of Bacteroidetes phylum in overweighed babies are found twice the normal weight
• Inverse association between an abundance of Staphylococcus and the length of the child at age 1 is less
compared to age 2

14. CONCLUSIONS
• The abundance of microbiome influence the over weight
• Proper microbiome flora is necessary to ensure the healthy individuals
• Obesity can be reduced by microbiome treatments
• Studies show that the prediction of obesity is possible
• Human microbiome market is gaining importance due to life style diseases

15. REFERENCES
• Davis C. D. (2016). The Gut Microbiome and Its Role in Obesity. Nutrition today, 51(4), 167–174.
• Peter J. Turnbaugh and Jeffrey I. Gordon,The core gut microbiome, energy balance and obesity,J
Physiol 587.17 (2009) pp 4153–4158
• Sridevi Devaraj, Peera Hemarajata, and James Versalovic, The Human Gut Microbiome and Body
Metabolism: Implications for Obesity and Diabetes, Clinical Chemistry 59:4 617–628 (2013)
• https://www.globenewswire.com/news-release/2019/04/01/1790907/0/en/Global-Human-
Microbiome-Market-to-2024-Increasing-Incidence-of-Lifestyle-Related-Diseases-and-Growing-
Geriatric-Population-Driving-Growth.html
• https://www.healio.com/pediatrics/neonatal-medicine/news/online/%7B33868b9c-295a-4eda-
98b4-59c941f7d74a%7D/microbiome-in-newborns-stool-can-predict-overweight-at-age-3-years
• http://eukaryoticmicrobe.blogspot.com/2018/12/priming-gut-how-organisms-inside-us-can.html