L IPID AND E NERGY M ETABOLISM

15.7.3 L IPID AND E NERGY M ETABOLISM

Obesity, diabetes, and hypercholesterolemia are increasingly widespread and play a synergistic role in the onset of coronary heart disease. The potential modulating role of probiotics and prebiotics in lipid and energy metabolism has therefore raised

Probiotics, Prebiotics, and Synbiotics

TABLE 15.9 Prebiotic, Probiotic, and Synbiotic in Children’s Health

Prebiotic/Probiotic/Synbiotic

Medium

Duration

Study Design

Decrease in constipation frequency; decrease Saavedra et al. 94 (1.1 g/kg/day)

Infant cereal (3.32

N.D.

Prospective, double-blind,

g/kg/day)

randomized, controlled study, n =

in the occurrence of febrile illness; decrease

123 children (4–24 months old)

in use of antibiotic; no change in incidence of diarrhea

Inulin (0.2 g/kg/day)

Cereal (5 g/kg/day)

10 weeks Double-blind, placebo-controlled

Increase in antimeasles IgG

Firmansyah et al. 95

trial, n = 50 weaned infants (7–9 months)

L. acidophilus + B. infantis +

Fisberg et al. 63 fructo-oligosaccharides

Supplement

4 months Multicenter, double-blind,

Decrease in number of sick days

randomized, placebo-controlled trial, n = 626 malnourished children (1–6 years old)

L. rhamnosus + fructo-

Ahmad et al. 96 oligosaccharides

Formula

N.D.

Double-blind, placebo-controlled,

Decrease of diarrhea duration

randomized trial, n = 58 children with acute gastroenteritis

Decrease in risk of diarrhea and shedding of Saavedra et al. 94 thermophilus

B. bifidum + Streptococcus

Formula

17 months Double-blind, placebo-controlled,

randomized trial, n = 55

rotavirus

hospitalized infants (5–24 months)

L. GG Oral rehydration

N.D.

Multicenter, double-blind, placebo- Decrease in duration of diarrhea

Guandalini et al. 97

controlled, randomized trial, n = 287 children with acute diarrhea

L. GG (2 ×10 10 CFU)

Fruit puree

2 months Double-blind, placebo-controlled

Decrease in diarrhea frequency

Costa-Ribeiro et

study, n = 118 lower socioeconomic

al. 98

children

Functional Food Carbohydrates

interest for several decades. Probiotics are thought to have cholesterol binding properties that stimulate the excretion of cholesterol in feces, instead of reabsorption by the host. 102 Good correlation exists in vitro and in animals for a cholesterol- lowering effect following treatments with probiotics and prebiotics. Results of human studies, however, are conflicting. Lactobacillus acidophilus, Lactobacillus bulgari- cus , Bifidobacterium longum, and Enterococcus faecium have been used in double- blind, randomized, placebo-controlled studies in humans, generating mixed results.

A recent review summarizing these human studies has highlighted that a moderate decrease in serum total cholesterol may occur with specific strains of probiotics. 102

The effect was not systematically reflected by changes in the serum concentration of LDL cholesterol or triacylglycerols. A decrease in the LDL/HDL (low-density

lipoprotein/high-density lipoprotein) ratio, an indicator of atherogenicity, may be observed in some studies, but this has been related to the fat content of the dairy

product used as the vehicle. 7 Human studies investigating the cholesterol-lowering effect of prebiotics have essentially focused on fructo-oligosaccharides and inulin with inconsistent findings. The most significant change was a substantial decrease in circulating triacylglycerols. The proposed mechanism is an inhibition of de novo lipogenesis in the liver. Prebiotics may also have a low glycemic index and help in reducing blood glucose and preventing insulin resistance, but the findings in humans are still preliminary. 103 Both inhibition of the de novo lipogenesis and modulation of insulin release may be mediated by SCFAs produced in the gut following the fermentation of inulin and fructo-oligosaccharides. 104 The complexity and heteroge- neity of lipid metabolism do not allow firm conclusions to be made on the protective effect of probiotics and prebiotics against coronary heart diseases.