PREBIOTICS, THE INTESTINAL MICROBIOME AND BONE HEALTH Corrie Whisner, PhD School of Nutrition and Health Promotion Arizona State University June 7, 2017
OVERVIEW 1. Osteoporosis 1. Prevalence 2. Prevention during childhood 2. Prebiotics and the Microbiome 1. Dietary means of impacting gut bacteria 2. Prebiotics 3. Mineral metabolism in adolescents 1. Prebiotic effects on calcium absorption 2. Prebiotic modification of gut microbiome 3. Potential Mechanisms 4. Future plans and research needs
OSTEOPOROSIS IS A COSTLY DISEASE Low bone mass and deterioration of bone micro-architecture 54 million Americans have osteoporosis and low bone mass www.nof.org www.webmd.com
OSTEOPOROSIS PREVENTION STARTS IN YOUTH Jasminka, et al. J Am Coll Nutr 2000; 19: 715.
CALCIUM REQUIREMENTS DON T MATCH INTAKE FOR TEENS INFANCY TO ADOLESCENCE CALCIUM (mg/d) 0-6 months -- 6-12 months -- 1-3 years 700 4-8 years 1000 9-13 years 1300 14-18 years 1300 Adolescent girls consume approximately 900-1000 mg/d Adolescent boys consume approximately 1000-1300 mg/d WOMEN CALCIUM (mg/d) 19-50 years 1000 Post-menopause (51+ years) 1200 During pregnancy/lactation 14-18 years 1300 During pregnancy/lactation 19-50 years 1000 WOMEN CALCIUM (mg/d) 19-70 years 1000 70+ years 1200 International Osteoporosis Foundation, www.iof.org; Bailey RL, et al. J Nutr. 2010;140(4):817-822.
MICROBIOME AND HEALTH OUTCOMES Microbiome Host-inhabiting microbes and genes NIH initiative and funding NIH Medical Arts and Printing Prebiotics affect the microbiome for health Janoff EN. Translational Research. 2017;179:1-6.
WHAT ARE PREBIOTICS? Found in fruits, vegetables and other plants Onions Leeks Artichokes Chicory Root Can be synthetic Associated with growth of beneficial bacteria in the lower gut Lactobacillus Bifidobacteria Lactobacillus Bifidobacteria
WHAT ARE PREBIOTICS? Basic criteria for selection of prebiotics: Resistance to digestion Hydrolysis and fermentation by colonic microflora Selective stimulation or growth of one or limited number of bacteria Beneficial health effects
PREBIOTICS ENHANCE MINERAL SOLUBILITY Blood Lumen OOH OOH + ph Ca Ca 2+ Ca 2+ Ca 2+ 2+ Ca : ) SCF = Soluble Corn Fiber (prebiotic); SCFA = Short chain fatty acids
Crypt Villus PREBIOTICS INCREASE INTESTINAL SURFACE AREA Crypt depth Epithelial cell density Cecal vein flow Net calcium transport 2-fold higher in cecum and distal colon * Scholz-Ahrens, et al. AJCN. 2001;73:459S. * Raschka, et al. Bone. 2005;37:728.
PREBIOTICS INCREASE INTESTINAL CALCIUM TRANSPORTERS Intestinal Villi Enterocyte 2+ Ca 2+ Ca TRPV6 2+ Ca Lumen Calbindin D 9k Blood ATPase
SCF IMPROVED BONE STRENGTH IN GROWING RATS Bone Parameter Change Total Body BMC (g) 7.6%* Total Body BMD (g/cm 2 ) 2.9%* Femur Volumetric BMD (mg/cm 3 ) 8.3%* Cortical Area (mm 2 ) 19.6%* Cortical Thickness (mm) 22.4%* Peak Breaking Force (N) 8.8%* * Significant difference from control, p<0.05 Weaver CM et al. J Agri Food Chem. 2010; 58: 8952
EFFICACY STUDY TO EVALUATE HUMAN EFFECTS OF SCF Double-blind, randomized controlled crossover Two, 3-week metabolic balance periods Controlled diets with 600 mg/d calcium and 15 g/d fiber PROMITOR Soluble Corn Fiber in fruit snacks Males and females participating in summer camp Subject Randomization N = 24 12 g/d delivered as Soluble Corn Fiber Control 12 g/d delivered as Soluble Corn Fiber Control 3 week intervention 1 week washout 3 week intervention
FRACTIONAL CALCIUM ABSORPTION TEST Calcium absorption test Oral dose: 15 mg 44 Ca 150 mg Ca in breakfast Final rising urine collection IV dose: 5mg 43 Ca Day 1 Day 2 0-24h urine 24-48h urine Pooled urine collections for ICP-MS analysis Fractional Ca Absorption= 44 Ca excess 43 Ca excess NA Ca44 NA Ca 43 iv dose oral dose
SUBJECT CHARACTERISTICS Mean + SD Race/Ethnicity: A=Asian, H=Hispanic, O=Mixed race/other *Significant difference between boys and girls (p = 0.009) **Significant difference between boys and girls (p = 0.01) Females (n=9) Males (n=15) Race / Ethnicity (A, H, O) A=2, H=5, O=2 A=9, H=1, O=5 Age (y) 13.3 ± 1.0 13.5 ± 0.9 Weight (kg) 59.9 ± 13.2 61.1 ± 11.8 Height (cm) 157.3 ± 4.9 164.9 ± 8.2 BMI (kg/m 2 ) 24.1 ± 4.0 22.4 ± 3.1 BMI Percentile (%) 80.0 ± 16.4 74.7 ± 19.2 Tanner Score Average 3.8 ± 0.7 2.4 ± 0.9 Lean mass (%) 61.2 ± 5.2 71.1 ± 9.5* Fat mass (%) 35.1 ± 5.6 25.1 ± 10.0** Total Body BMD (g/cm 2 ) 1.07 ± 0.11 1.04 ± 0.11 Total Body BMC (g) 2115 ± 329 2316 ± 424 Whisner CM, et al. Br J Nutr. 2014;112(3):446.
Fractional Calcium Absorption SCF INFLUENCED LATE PHASE CALCIUM ABSORPTION Calcium absorption increased by 12% with SCF consumption compared to Control Time effect consistent with lower gut absorption Whisner CM, et al. Br J Nutr. 2014;112(3):446. 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 *P = 0.02 0-24 h 24-48 h 24 Hour Urine Pools SCF Control
MICROBIAL DIFFERENCES AT THE KINGDOM LEVEL OBSERVED B=baseline measure; E=end of treatment measure * Significant difference from that of respective B sample, p<0.05 Whisner CM, et al. Br J Nutr. 2014;112(3):446.
BACTERIAL FAMILIES CHANGED WITH SCF TREATMENT Group differences, P < 0.05 Whisner CM, et al. Br J Nutr. 2014;112(3):446.
Correlation with Change in Ca Absorption CALCIUM ABSORPTION CORRELATED WITH FERMENTERS 0.8 0.6 0.4 ** ** * * * * P < 0.05 ** P < 0.01 0.2 0-0.2-0.4-0.6 * Bacteroidetes Firmicutes Change in Microbial Communities (Genus Level) Whisner CM, et al. Br J Nutr. 2014;112(3):446.
Fractional Calcium Absorption Increase in Ca Absorption (%) BENEFIT OF SCF DIFFERED BY PERSON RESPONDER EFFECT 1.2 35 P < 0.05 1 30 25 0.8 20 15 0.6 10 5 0.4 0 0.2-5 -10 0 Control SCF -15 Non-responder Responder Whisner CM. Unpublished data.
FEASIBILITY AND DOSE-RESPONSE TRIAL WITH SCF Double-blind, randomized controlled crossover Three, 4-week supplementation sessions Controlled diets with 800 mg/d calcium and 15 g/d fiber PROMITOR Soluble Corn Fiber in muffins and fruit drinks Females consuming products at home 10 g/d delivered as Soluble Corn Fiber 10 g/d delivered as Soluble Corn Fiber Subject Randomization N = 30 20 g/d delivered as Soluble Corn Fiber 20 g/d delivered as Soluble Corn Fiber Control Control Whisner CM, et al. J Nutr. 2017;147(7):1298. 4 week intervention 3-4 week washout 4 week intervention
SUBJECT CHARACTERISTICS Characteristic Value Race, n (%) white 31 (100) Age, y 13.6 ± 1.0 Tanner score 4 ± 1 Postmenarcheal age, mo 18.9 ± 14.1 BMI, kg/m 2 21.2 ± 2.5 BMI percentile, % 68 ± 22 Total body BMD, g/cm 2 1.1 ± 0.1 Total body BMC, g 2130 ± 360 Body fat, % 31.0 ± 4.7 Whisner CM, et al. J Nutr. 2017;147(7):1298.
Fractional Calcium Absorption CALCIUM ABSORPTION INCREASED WITH BOTH TREATMENTS 0.47 0.45 0.43 0.41 0.39 0.37 0.35 0.33 00 g g SCF fiber/d from SCF 10 10 g g SCF fiber/d from SCF 20 20 g g SCF fiber/d from SCF 12.9±3.6% greater than control p=0.042 13.3±5.3% greater than control p=0.026 0.31 Whisner CM, et al. J Nutr. 2017;147(7):1298. 12 24 36 48 Time (hours)
MICROBIAL COMMUNITY STRUCTURE DIFFERED WITH SCF PC2 9.5% variation explained With"SCF" No"SCF" B-0 g/d SCF B-10 g/d SCF B-20 g/d SCF E-0 g/d SCF E-10 g/d SCF E-20 g/d SCF Whisner CM, et al. J Nutr. 2017;147(7):1298. PC1 12.1% variation explained B=Beginning E=End
MICROBIAL GENERA DIFFERED AFTER SCF CONSUMPTION Phylum Genus 0 g/d fiber from SCF (%) 10 g/d fiber from SCF (%) 20 g/d fiber from SCF (%) P value 0 vs 10 g/d P value 0 vs 20 g/d P value 10 vs 20 g/d Actinobacteria Bifidobacterium 3.2 ± 3.2 4.2 ± 3.3 5.1 ± 4.3 ns 0.047 ns Bacteroidetes Parabacteroides 1.1 ± 0.8 2.1 ± 1.6 3.0 ± 2.0 0.022 0.0004 0.021 Firmicutes Anaerostipes 0.2 ± 0.1 0.1 ± 0.1 0.1 ± 0.1 0.0074 0.0332 ns Firmicutes Dorea 1.3 ± 0.6 1.0 ± 0.6 0.7 ± 0.3 ns 0.0022 0.06 Firmicutes reclassified 2 Ruminococcus 3.7 ± 1.9 2.4 ± 0.9 1.9 ± 1.2 0.0036 0.0068 ns unclassified 2 Firmicutes 6.3 ± 2.6 11.4 ± 5.1 13.1 ± 5.8 Lachnospiraceae 0.0004 0.0007 ns Firmicutes Dialister 0.5 ± 0.7 0.9 ± 1.0 1.2 ± 1.0 ns 0.0089 ns Whisner CM, et al. J Nutr. 2017.
Fecal weight, g/d FECAL WEIGHT DID NOT CHANGE SIGNIFICANTLY WITH SCF 120 100 80 60 40 20 0 0 10 20 SCF (g fiber/day) Whisner CM, et al. J Nutr. 2017;147(7):1298.
Fecal ph FECAL PH CHANGED SIGNIFICANTLY WITH 20 GRAMS SCF 8 7 a a b 6 5 4 3 2 1 Whisner CM, et al. J Nutr. 2017;147(7):1298. 0 0 g 10 g 20 g 0 10 20 SCF (g fiber/day) Model P < 0.02
Fecal SCFA, mmol/d SHORT CHAIN FATTY ACIDS DID NOT DIFFER BY TREATMENT 16 14 12 10 8 6 4 2 0 0 g 10 g 20 g 0 10 20 SCF (g fiber/day) Whisner CM, et al. J Nutr. 2017;147(7):1298.
CONCLUSIONS Daily intake of PROMITOR Soluble Corn Fiber improves calcium absorption in adolescents Increased absorption occurs between 24-48 h post-treatment Improvements in absorption correlate with starch and fiber fermenting microbes Exact mechanisms remain unclear or require larger sample size
FUTURE EFFORTS Easier ways to visualize and interpret these data with minimal bias/false positives Racial and sex differences require further exploration Further work is needed to understand individual responses to prebiotics Make non-responders respond to treatments with synbiotics
ACKNOWLEDGEMENTS Funding: Tate & Lyle Health & Nutrition Sciences Collaborators: Connie Weaver, Berdine Martin, Cindy Nakatsu, George McCabe, Linda McCabe
http://www.xkcd.com/1543/ QUESTIONS?