Uptake, inter-organ distribution and metabolism of dietary putrescine in the rat

Personalizing protein nourishment

Proteins are not equally digestible-their proteolytic susceptibility varies by their source and processing method. Incomplete digestion increases colonic microbial protein fermentation (putrefaction), which produces toxic metabolites that can induce inflammation in vitro and have been associated with inflammation in vivo. Individual humans differ in protein digestive capacity based on phenotypes, particularly disease states. To avoid putrefaction-induced intestinal inflammation, protein sources, and processing methods must be tailored to the consumer's digestive capacity. This review explores how food processing techniques alter protein digestibility and examines how physiological conditions alter digestive capacity. Possible solutions to improving digestive function or matching low digestive capacity with more digestible protein sources are explored. Beyond the ileal digestibility measurements of protein digestibility, less invasive, quicker and cheaper techniques for monitoring the extent of protein digestion and fermentation are needed to personalize protein nourishment. Biomarkers of protein digestive capacity and efficiency can be identified with the toolsets of peptidomics, metabolomics, microbial sequencing and multiplexed protein analysis of fecal and urine samples. By monitoring individual protein digestive function, the protein component of diets can be tailored via protein source and processing selection to match individual needs to minimize colonic putrefaction and, thus, optimize gut health.

Dietary putrescine (1,4-diaminobutane) influences recovery of Turkey poults challenged with a mixed coccidial infection

Exogenous dietary putrescine (1,4-diaminobutane) can increase growth rates of neonatal animals, including calves, chicks, and piglets, under nutritional stress. Turkey poults often have a high mortality rate and this may be due to poor initial feeding behavior and inadequate development of the intestinal tract. We conducted an experiment to determine the effect of dietary putrescine supplementation on growth performance and the role of dietary putrescine in prevention and recovery from a coccidial challenge. A total of 160 1-d-old turkey poults were fed a corn and soybean meal-based starter diet supplemented with 0.0 (control), 0.1, 0.2, and 0.3 g/100 g purified putrescine (8 birds/pen, 5 pens/diet). At 14 d of age, half the birds were infected with approximately 43,000 sporulated oocysts. The experiment lasted 24 d. Fecal samples were gathered from d 3 to d 5 postinfection by total collection. Ten control and 10 infected birds fed each diet were sampled on d 6 and d 10 postinfection. The induced infection produced significant depressions in growth and feed intake and detrimental morphological changes in the small intestine of poults in the absence of mortality. Weight gains, protein content of jejunum, and morphometric indices of duodenum, jejunum, and ileum were greater in challenged poults fed 0.3 g/100 g putrescine than in controls. We conclude that dietary putrescine supplementation may be beneficial to poult growth, mucosal development of the small intestine, and to recovery from subclinical coccidiosis.

Fate of orally administered 15N-labeled polyamines in rats bearing solid tumors

We studied absorption, distribution, metabolism, and excretion of polyamines (putrescine, spermidine, and spermine) in the gastrointestinal tract using (15)N-labeled polyamines as tracers and ionspray ionization mass spectrometry (IS-MS). The relatively simple protocol using rats bearing solid tumors provided useful information. Three (15)N-labeled polyamines that were simultaneously administered were absorbed equally from gastrointestinal tract, and distributed within tissues at various concentrations. The uptake of (15)N-spermidine seemed preferential to that of (15)N-spermine since the concentrations of (15)N-spermidine in the liver and tumors were higher, whereas those of (15)N-spermine were higher in the kidney, probably due to the excretion of excess extracellular spermine. Most of the absorbed (15)N-putrescine seemed to be lost, suggesting blood and tissue diamine oxidase degradation. Concentrations of (15)N-spermidine and (15)N-spermine in the tumor were low. We also describe the findings from two rats that were administered with (15)N-spermine. The tissue concentrations of (15)N-spermine were unusually high, and significant levels of (15)N-spermidine were derived from (15)N-spermine in these animals.

Simultaneous determination of endogenous and orally administered (15)N-labeled polyamines in rat organs

A method for the simultaneous determination of polyamines (putrescine, spermidine, and spermine) by ionspray ionization-mass spectrometry was modified to determine (15)N-labeled polyamines together with unlabeled polyamines using (13)C,(15)N double-labeled polyamines as internal standards. This technique permitted the use of (15)N-labeled polyamines as tracer compounds to follow polyamine biosynthesis, interconversion, and absorption. The method was used to examine the organ distribution of orally administered (15)N-labeled polyamines in rats. Each (15)N-labeled polyamine was taken up by the three organs tested: the small intestine, liver, and kidney. The uptake of (15)N-labeled spermidine was greater than that of (15)N-labeled spermine and putrescine. Administration of a mixture of (15)N-labeled polyamines was useful for determining the disposition of each (15)N-polyamine absorbed from the intestinal tract.

The human gut bacteria Bacteroides thetaiotaomicron and Fusobacterium varium produce putrescine and spermidine in cecum of pectin-fed gnotobiotic rats

Pectin is a soluble indigestible polysaccharide that stimulates cecal polyamine formation in rats. Bacteroides and fusobacteria, two numerically dominant bacterial population groups in the large intestine, were found to synthesize in vitro high amounts of spermidine and putrescine. The purpose of this study was to elucidate the effect of pectin on the polyamine production by defined bacterial species in vivo. Germfree male Wistar rats (n = 18) were randomly assigned to one of three treatments: (i) monoassociation with Bacteroides thetaiotaomicron + fiber-free diet; (ii) diassociation with B. thetaiotaomicron + Fusobacterium varium + fiber-free diet or (iii) diassociation with B. thetaiotaomicron + F. varium + fiber-free diet + 10% pectin. The cecal contents of monoassociated rats fed fiber-free diet contained large amounts (1.51+/-0.21 micromol/dry total cecum content) of spermidine which was the major polyamine. The cecum of diassociated rats fed the fiber-free diet contained even higher concentrations of spermidine (2.53+/-0.21 micromol/dry total cecum content) and also putrescine, which was now the dominant polyamine (putrescine 0.32+/-0.28 vs. 3.01+/-0.28 micromol/dry total cecum content; monoassociation vs. diassociation). Pectin consumption by diassociated rats led to an additional increase in the cecal concentrations of all polyamines: putrescine, spermidine and spermine were 40, 37 and 100%, respectively, higher in the diassociated rats consuming the pectin diet than in those consuming the pectin-free diet. Since the microbial counts in the cecum did not differ in the diassociated treatment groups, the elevated concentrations of polyamines observed in the pectin group must have been due to stimulated bacterial polyamine synthesis. The decline of individual polyamines from cecum to feces detected at the end of the study in all treatment groups and the high microbial counts in the cecum and in feces suggest that bacterial polyamines are absorbed in cecum and colon. Pectin stimulates intestinal microbes to synthesize large amounts of polyamines which may be utilized by the host.