While probiotic supplements can provide a number of benefits, it should be realized that a dose of supplemented probiotics will typically only last about two weeks in the intestines. Should we keep taking them we can maintain these levels, but two weeks after we stop, we will lose most if not all of those supplemented colonies.
However, most of us also maintain billions of lifelong probiotic bacteria species. These can become knocked down by pathogenic bacteria as well as antibiotics.
But if we feed our body's own probiotics with good prebiotic foods, we can boost our body's own colonies, which will benefit the body even greater than taking supplemental probiotics.
To this end, it is best to know what foods provide the biggest bang for our buck in terms of feeding our probiotics. In my book on the topic, I discuss a number of prebiotic foods. But here we introduce another two significant prebiotic foods: Almonds and pistachios.
USDA studies both almonds and pistachios
A 2015 study from the University of Florida and the USDA's Agricultural Research Service, Beltsville Human Nutrition Research Center tested human consumption of almonds and pistachios.The research, published in the British Journal of Nutrition, consisted of two studies involving 18 and 16 people respectively.
In the 18-person study, researchers gave the volunteers three servings of almonds a day, one and a half servings or no almonds for a period of 18 days.
During that period the researchers conducted stool examinations of the subjects. The fecal matter was analyzed for microorganisms using an RNA sequencing analytical method.
In the second study, the researchers tested 16 volunteers, who were given no pistachios, 1.5 servings of pistachios or three servings of pistachios per day for 18 days.
Both studies utilized a crossover design, which means that each of the volunteers underwent each of the dosages during successive study periods.
Lactobacilli boosted by both
The researchers found that in both study groups, the pistachio and almond eaters maintained higher colonies of Lactobacilli bacteria compared to those who ate no nuts during the 18 days. These included Lactobacillus acidophilus and others.While both nuts increased probiotic colonies, the research found the pistachio nuts produced greater improvements in probiotics than the almonds.
However, neither affected bifidobacteria colonies, which primarily live within the colon.
The researchers noted the bacteria promoted by the nuts were beneficial butyrate-producing probiotics. Butyrate production by probiotics has been found in other research to help prevent colon and rectal cancer.
The researchers concluded:
"Increasing the consumption of almonds or pistachios appears to be an effective means of modifying gut microbiota composition."
Raw and roasted almonds boost probiotics
A 2016 study tested both raw and roasted almonds. The researchers found that both raw and roasted almonds boosted lactobacilli and bifidobacteria.
In this four-week study, the researchers also found that the almond consumption inhibited Enterococcus species of bacteria in the gut. Enterococcus bacteria are a major source of dysbiosis and dysentery.
The researchers found that the raw almonds boosted bifidobacteria greater than the roasted almonds did. Perhaps this explains some of the lack of performance in the 2014 study.
Raw almonds also produced better intestinal health, including higher β-galactosidase levels and lower β-glucuronidase and azoreductase levels. The latter two enzymes have been linked to colon cancer.
Pistachio hulls contain significant prebiotics
Many consume pistachios in the hulls, separating the hull from the nut and spitting out the hull. Munching a few of these hulls is not a bad idea either.In a 2018 study from Rutgers University, researchers found that the hulls of pistachios contain a number of prebiotic compounds. The researchers referred to the collection as "pistachio hull polysaccharides." The researchers found that the prebiotic blend from pistachio hulls provided prebiotic activity that rivals inulin.
Inulin is one of the central prebiotics provided in many supplements and prebiotic-boosted foods.
The researchers also found the pistachio prebiotic remained primarily intact until it was able to help ferment healthy bacteria. They found that Lactobacillis rhamnosus and L. plantarum were significantly boosted as a result of the consumption of the pistachio hull polysaccharides.
So don't be shy about munching a few hulls while you eat your pistachios. Both will increase your body's probiotic colonies.
Eating nuts also extends life in other research
It is now no surprise that eating nuts decreases the risk of mortality. For example, Harvard researchers found that among 76,464 women and 42,498 men, those who ate nuts seven or more times per week had a 20 percent reduced mortality rate compared to those who did not eat much in the way of nuts.The research also found that the more nuts were eaten, the lower the mortality rates were. The research was based on the Nurses' Health Study and the Health Professionals Follow-up Study.
The research also found the more nuts were eaten, the lower the risk of cancer, heart disease and lung diseases.
Some of the reason nuts have such a beneficial effect upon the cardiovascular system is due to their producing a group of compounds called urolithins.
As discussed, urolithins boost the health of our blood vessel walls, and help prevent the build up of artery plaque, known as atherosclerosis.
This mechanism relates to the waste byproducts of probiotics versus the waste streams of pathogenic bacteria. Pathogenic bacteria produce toxic waste streams called endotoxins.
Endotoxins pollute the bloodstream with easily-oxidized and easily-radicalized chemicals that essential damage blood vessels and organs. This endotoxin damage is linked to vascular disease.
REFERENCES:
Liu Z, Wang W, Huang G, Zhang W, Ni L. In vitro and in vivo evaluation of the prebiotic effect of raw and roasted almonds (Prunus amygdalus). J Sci Food Agric. 2016 Mar 30;96(5):1836-43. doi: 10.1002/jsfa.7604.Akbari-Alavijeh S, Soleimanian-Zad S, Sheikh-Zeinoddin M, Hashmi S. Pistachio hull water-soluble polysaccharides as a novel prebiotic agent. Int J Biol Macromol. 2018 Feb;107(Pt A):808-816. doi: 10.1016/j.ijbiomac.2017.09.049.
Bao Y, Han J, Hu FB, Giovannucci EL, Stampfer MJ, Willett WC, Fuchs CS. Association of nut consumption with total and cause-specific mortality. N Engl J Med. 2013 Nov 21;369(21):2001-11. doi: 10.1056/NEJMoa1307352.
Ukhanova M, Wang X, Baer DJ, Novotny JA, Fredborg M, Mai V. Effects of almond and pistachio consumption on gut microbiota composition in a randomised cross-over human feeding study. Br J Nutr. 2014 Jun 28;111(12):2146-52. doi: 10.1017/S0007114514000385.