Assessing Gut Issues: Short Chain Fatty Acids Elizabeth Redmond, PhD, MMSc, RD

Transcription

1 Assessing Gut Issues: Short Chain Fatty Acids Elizabeth Redmond, PhD, MMSc, RD Chair-Elect Dietitians in Integrative and Functional Medicine DPG Education Specialist, Metametrix Laboratory, Georgia

2 Short Chain Fatty Acids (SFCA) This session will discuss: 1. What are SCFA? 2. What do SCFA do? 3. What affects SCFA production? 4. Review of the synergistic relationship of SCFAs and gut bacteria. 5. Possible treatments and case study.

3 1. What are short chain Putrefactive fatty acids SCFA (SCFA)? Predominant gut bacteria ferment dietary fiber and their monosaccharide components to acetate, propionate, and butyrate, and protein material to valerate, isovalerate and isobutyrate. C-2 Acetate C-3 Propionate C-4 Butyrate C-6 Caproate ic4 isobutyrate C-5 Valerate* ic5 isovalerate ic6 hexanoate Saccharolytic (carbohydrate) fermentation SCFA: >90% of SCFA Proteolytic (Protein) fermentation SCFA: < 10% of SCFA

4 An overview of the relationship between transit of food through the human gastrointestinal tract and the digestion of nutrients in the small intestine and fermentation in the cecum and colon. Topping D L, Clifton P M Physiol Rev 2001;81:

5 1. What do SCFAs do? More than 95% of SCFA are produced and absorbed within the colon. SCFA contribute to normal large bowel function and prevent pathology through their actions in the lumen and on the colonic musculature and vasculature, and through their metabolism by colonocytes. Topping, D., Clifton, P. Physiol Rev July 1, 2001 vol. 81 no

6 Acetate Butyrate Propionate Immune system Immune system Immune system Carcinogenesis Carcinogenesis Carcinogenesis Colonic function Colonic function Colonic function Adipogenesis Satiety Satiety Barrier function Neurological effects Visceral perception Cholesterol metabolism Insulin sensitivity Oxidative stress Journal of AOAC International Vol. 95, No. 1, 2012

7 Butyrate has been shown to: Acts as a signal metabolite affecting epithelial cell proliferation, apoptosis, and differentiation. Affects several inflammatory parameters such as cytokines and myeloperoxidase activity, thus increasing antioxidant capacity. Provides barrier function: stimulates intestinal mucus production, mucosal repair, and decreases colonic epithelial permeability. Enhances the growth of lactobacilli and Bifidobacter sp. Increases mucosal blood flow. Increases in vitro crypt proliferation. Clinically can reduce inflammation and diarrhea. Possible protection against colonic carcinogenesis. Increases glutathione production. Neurogastroenterol Motil (2011) 23,

8 Acetate has been shown to: Decreases lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNFα) release from human neutrophils. Inhibits NF-κB reporter activity in human colon carcinoma cells. Intravenous administration increases peripheral blood antibody. Production of natural killer cell activity in cancer patients. Stimulates proliferation of normal crypt cells. Enhances ideal motility and increases colonic blood flow. May have a role in adipogenesis. Neurogastroenterol Motil (2011) 23,

9 Propionate has been shown to: Inhibits proinflammatory eicosanoids, nuclear factor-κb, adhesion molecules, LPS-stimulated TNF-α Regulates and inhibits proliferation of activated lymphocytes Growth arrest and differentiation of human colon cancer cells Induces colorectal cancer apoptosis Lowers blood glucose and alters lipid metabolism in healthy human subjects Increases satiety - Increases production of leptin Upregulates peroxisome proliferator activated receptor (PPAR)- gamma Activates G protein-coupled receptor and inhibits lipolysis Intraventricular infusions can impair social behavior and cause brain abnormalities in rats, similar to those detected in human autism. Neurogastroenterol Motil (2011) 23,

10 Other clinical uses of SCFA: acetate/propionate ratio Acetate has been shown to increase cholesterol synthesis. Propionate has been shown to inhibit cholesterol synthesis. Treatments that can decrease the acetate/propionate ratio have been proposed as a way to reduce serum lipids. J Clin Gastroenterol Mar;40(3):

11 Valerate is0butyrate isovalerate inhibitory effects on cytokine release increase of glutathione (GSH) induce histone hyperacetylation inhibitory effects on cytokine release excellent substrate for colonic oxidation, similar to butyrate strong pungent cheesy or sweaty smell proposed that it is the anticonvulsant agent in valerian major component of the cause of unpleasant foot odor Journal of AOAC International Vol. 95, No. 1, 2012

12 The breakdown Protein of proteins Breakdown and peptides by colonic microorganisms. Proteins (from foods, albumin, blood, muscle, secretions) must be broken down to peptides and amino acids before bacteria can metabolize them. Proteins get broken down by bacterial proteases and peptidases, and pancreatic endopeptidases. The end product of the breakdown is SCFA, BCFA and organic acids.

13 Metabolism of N-containing substrates in the large gut, and the physiologic significance of the end products.

14 What affects production of SCFAs? Fecal ph Diet BMI Predominant bacteria Location/Environment Immune Inflammation Race Gender Transit time

15 ph Concentration (mmol g dry wt bacteria) ph 6.8 ph 5.5 Free amino acids Acetate Propionate Butyrate Valerate ibutyrate ivalerate Total SCFA grown in mixed cultures of intestinal bacteria from amino acids, with a change in ph value.

16 Diet High-protein, reduced-carbohydrate weight-loss diets promote metabolite profiles likely to be detrimental to colonic health. M (mmol/l) - -> Total SCFA acetate propionate butyrate valerate isovalerate isobutyrate maintenance high-protein /moderatecarbohydrate (HPMC) high-protein /lowcarbohydrate (HPLC) P <0.001 <0.001 <0.001 <0.001 <0.083 <0.001 <0.002 Short-chain fatty acids (SCFAs) detected in feces of 17 volunteers given 3 different diets. Am J Clin Nutr May 2011 vol. 93 no

17 Level of SCFA in three diet groups **= <0.001; *= 0.001; ^=.01 ^ * Maintance HPMC HPLC Am J Clin Nutr May 2011 vol. 93 no

18 Proteolytic fermentation Saccharolytic fermentation Percent SCFA for three diet groups ** isovalerate isobutyrate ** * valerate butyrate * ^ propionate HPLC HPMC Maintanance acetate Percent Am J Clin Nutr May 2011 vol. 93 no **= <0.001; *= 0.001; ^=.01

19 Diet/supplements Diet with resistant starch (1.53 kg/10 kg of diet) Diet supplemented with cellobiose (9%) Fiber supplementation (5%) Oral butyrate (10 mg/kg) Effects on SCFAs or their derivatives in inflammatory conditions Improvement of symptoms; epithelial cell proliferation; regeneration of laminin; growth of intestinal bacteria Reduction of weight loss; diminished tissue edema; attenuation of inflammatory cytokine concentrations Reduction in MPO and NO synthase activities; restoration of colonic glutathione levels; diminished TNFconcentrations Improvement of mucosa lesion and attenuation of the inflammatory profile of intestinal mucosa and local lymph nodes in a model of DSS-induced colitis. Nutrients 2011, 3

20 Factors affecting protein fermentation The amount of protein entering the colon depends on the amount of protein and the digestibility of the protein eaten. Decreased digestibility = increased protein fermentation. Digestibility of proteins from animal sources exceeds 90%; plant proteins range from 70 90%. On a normal mixed diet, the amount of protein has a stronger effect on the amount reaching the colon. Mol. Nutr. Food Res. 2012, 56, ; November 1, 2010 vol. 299 no. 5 G1030-G1037

21 Carbohydrate Gap o Fiber is comprised principally of polysaccharides and non-starch polysaccharide (NSP). NSP resist digestion by intrinsic human intestinal digestive enzymes completely, their intakes do not account for calculated human SCFA production (the carbohydrate gap ). o Some of the deficit may be filled by oligosaccharides (OS), but starch and products of small intestinal starch digestion are thought to contribute the most. This fraction is termed resistant starch (RS). o A particular problem is that assay procedures are well-established for fiber and/or NSP but not for RS. This means that dietary intakes can be calculated for the former but not the latter, and direct comparison may be difficult. Thus health authorities have been able to make dietary recommendations for fiber but not yet for RS. Topping D L, Clifton P M Physiol Rev 2001;81: :

22 Percentage of carbohydrate loss in relation to GI [adapted from Jenkins et al.] Wong J M W, Jenkins D J A J. Nutr. 2007;137:2539S-2546S;

23 BMI Percent SCFA for three BMI levels * * Mean SCFA (mmol/l) * BMI BMI BMI 30+ Obesity (2009) 18,

24 Percent SCFA for three BMI levels > isovalerate isobutyrate valerate propionate butyrate acetate Percent of total SCFA Obesity (2009) 18,

25 Predominant Bacteria Predominant bacteria, or normal indigenous microflora, have co-evolved with their host, and play a major role in health. They provide: Colonization resistance against potentially pathogenic organisms Aid in digestion and absorption Produce vitamins and SCFAs Stimulate the GI immune system Are able to activate innate and adaptive immunity

26 SCFA Production Acetate Propionate Butyrate Lactate Bacteroides x x X (D) Bifidobacteria x X (L) Lactobacilli x X (D/L) Clostridia x x x X (L) Faecalibacteria x X (D) Fusobacteria x x Prevotella X

27 GI tract with bacteria populations shown by region Anaerobes dominate the gut.

28 Bacteroidetes Bacteroides spp. Prevotella spp. Firmicutes Clostridia spp. Mycoplasma spp. Lactobacillus spp. Proteobacteria Escherichia coli. Fusobacteria Fusobacteria spp. Actinobacteria Bifidobacter spp. Streptomyces spp. Bacterial Phylumm

29 Predominant Bacteria based on diet F. prausnitzil Roseburia ** Lachnospiraceace HPLC HPMC Maintanance Bacteroides * Am J Clin Nutr May 2011 vol. 93 no ** p= <.001; * p<.05

30 Bifidobacter content in RATS fed varying diets CT Control diet ; HF High fat diet HF-Cell High fat with non-fermentable fiber HF-OFS High fat with fermentable fiber

31 Dietary levels of oligofructose and Bifidobacter sp. resulted in a decrease in aberrant crypts in RATS aberrant crypts per/cm2 J Nutr Jul;129(7 Suppl):1483S-7S OF Oligofructose (inulin) SBO Soybean oligosaccharide; WBO Wheat bran oligosaccharide

32 Comparative study in children from Europe (EU) and rural Africa (BF) PNAS August 17, 2010 vol. 107 no

33 SCFA-producing bacteria could help to prevent establishment of some potentially pathogenic intestinal bacteria. Quantification of SCFAs in fecal samples from BF and EU populations by SPME-GC-MS. PNAS August 17, 2010 vol. 107 no

34 Comparative study in children from Europe (EU) and rural Africa (BF) Valerate 1.70% 1.20% Propionate Butyrate 20.10% 8.30% 13.64% 33.92% EU BF Acetate 51.17% 69.54% 0% 20% 40% 60% 80% 100% PNAS August 17, 2010 vol. 107 no

35 Comparative study in children from Europe (EU) and rural Africa (BF) fiber carbohydrate* fat protein EU BF PNAS August 17, 2010 vol. 107 no Grams of macronutrients

36 Environment Frequency of genes relayed to butyrate, acetate and propionate production in the fecal metagenome of 27 subjects. Nature, 2012;

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38 Immune Reactions Fecal Short Chain Fatty Acids in Children with Inflammatory Bowel Disease J. Pediatr Gastroenterol Nutr, Vol. 18, No. 2, White bars= controls; black = severe UC; grey= inactive/mild UC

39 Inflammation Amount of SCFAs in each population isobutyratelactate * propionate * butyrate IBS Healthy acetate Open Biochem J. 2010; 4: (*P<0.05).

40 Race Colonic contents of the primary SCFA in African Americans, Caucasian Americans, and Native Africans. O'Keefe S J D et al. J. Nutr. 2009;139:

41 Case Study Patient symptoms belching flatulence bloating abdominal pain diarrhea fatigue

42 Collect Diet history - vegetarian diet - tries to avoid dairy Symptom questionnaire- meets criteria for IBS Symptom history Laboratory assessment of GI function Do a stool test Look to see if the patient has vitamin D, B12, or iron Consider getting these or other fat soluble vitamins Also consider amino acids

43 Resident Micro-biota

44 Short Chain Fatty Acids Acetate / Propionate = 48/4.5= Average A/P ratio = Total cholesterol: 209 HLD: 41 and Lp(a): 75

45 Percent Short Chain Fatty Acids Saccharolytic fermentation Proteolytic fermentation (Isobutyrate + isovalerate + valerate) Case HPLC Maintenance Normal BMI Percent

46 Evaluation of Digestive Markers

47 Thermogram Results

48 Treatment options Use of butyrate Butyrate functions as the major energy source for colonocytes and modulates several cellular processes Changes in dietary habits Increasing fiber intake of soluble fibers (fermentable) is more effective than insoluble (non-fermentable), which can increase SCFAs (butyrate). Decrease total protein intake, or shift to more plant protein. This will result in a shift from proteolytic to saccharolytic fermentation. Exclude dairy and casein Use of prebiotics Specifically inulin Product Klaire labs Biotagen Increase diet sources: artichoke hearts, banana, agave, garlic, onion, wild yam, chicory

49 Assessing Gut Issues: Short Chain Fatty Acids Elizabeth Redmond, PhD, MMSc, RD Metametrix Laboratory, Georgia Chair-Elect Dietitians in Integrative and Functional Medicine DPG