UN­DER THE MI­CRO(BIOME) SCOPE

ZOOMER Magazine - - VITALITY -

ABOUT a decade ago, sci­en­tists in­tro­duced the world to a new con­cept so po­ten­tially ex­cit­ing that it made genome map­ping sud­denly seem like yes­ter­day’s news. This time, the re­ports were of the hu­man mi­cro- biome, the tril­lions of di­verse bac­te­ria that live on our skin, in our mouths, our in­testines and gen­i­tal tracts. In the years since, re­searchers have pieced to­gether what role the mi­cro­biome plays in phys­i­cal and men­tal health (spoiler alert: top billing), link­ing an un­healthy one with ev­ery­thing from asthma and obe­sity to de­pres­sion and car­dio­vas­cu­lar dis­ease. They’re also dis­cov­er­ing how we hu­mans – mere hous­ing units for all that bac­te­ria, as it turns out – are mess­ing with our mi­cro­biomes and what the con­se­quences of do­ing so might be.

As they learn more and more about the big pic­ture, sci­en­tists are now able to tar­get the re­search more pre­cisely. Re­cently, their fo­cus has turned in part to the mi­cro­biome in older and el­derly in­di­vid­u­als, and what they’re dis­cov­er­ing is both sober­ing and ex­cit­ing. One find­ing: ac­cord­ing to Brett Fin­lay, a pro­fes­sor at the Univer­sity of Bri­tish Columbia and au­thor of The WholeBody Mi­cro­biome, the mi­crobi-

ome in the 65-plus pop­u­la­tion “goes off a cliff in terms of com­po­si­tion.”

Dur­ing the ag­ing process, the in­testines be­come more per­me­able, and the di­ver­sity of ben­e­fi­cial mi­crobes de­creases – a sort of re­verse process to what hap­pens in the first few years of life, when the mi­cro­biome is de­vel­op­ing. The ben­e­fi­cial mi­crobes help pro­tect the gut from in­flam­ma­tion and, as they de­crease, they leave room for oth­ers as­so­ci­ated with in­flam­ma­tion to move in. “The Achilles heel to ag­ing is this chronic low-grade in­flam­ma­tion,” ex­plains Fin­lay.

One Bri­tish study in­di­cated that if peo­ple brush their teeth three times a day, as op­posed to two, their de­men­tia po­ten­tial de­creases by 20 to 40 per cent. Brush­ing more of­ten “de­creases the mi­crobe pieces seep­ing into your body, and these pieces piss off the im­mune sys­tem and cause in­flam­ma­tion,” he adds. “As you get older, the im­mune sys­tem qui­ets down a bit, and it’s thought that that causes changes in your mi­crobes.” In ad­di­tion, in­testi­nal per­me­abil­ity in­creases as we age, so mi­crobes are seep­ing into the body at a low rate, says Fin­lay, “which trig­gers low-grade in­flam­ma­tion, which then trig­gers tis­sue dam­age, which then trig­gers ... and then you just fill in what­ever Western dis­ease you want.”

Add to that de­creased amounts of ex­er­cise and the no­to­ri­ously un­healthy se­nior diet, light on the pro­tein, fresh fruit and veg­eta­bles and heavy on the pro­cessed foods, carbs and salt – par­tic­u­larly in long- term care or re­tire­ment homes. “It’s ap­ples and or­anges,” Fin­lay notes. “You com­pare some­one in an el­der­care place ver­sus liv­ing in a com­mu­nity: their mi­crobes are very dif­fer­ent.” And even in a com­mu­nity, peo­ple over 50 also tend to be de­fi­cient in such things as iron and vi­ta­mins B, B12 and D, as well as folic acid.

And while we’re def­i­nitely liv­ing longer, thanks mainly to a de­crease in in­fec­tions cour­tesy of an­tibi­otics and vac­cines, other Western dis­eases – Type 2 di­a­betes, COPD, obe­sity, al­ler­gies – are mov­ing in to take their place. Fin­lay calls it the hy­giene hang­over. “If clean is good, cleaner’s bet­ter, right? Not nec­es­sar­ily,” he says. “In our quest to get rid of the in­fec­tive agents, which we’ve done a very good job of, we’ve wiped out many of the mi­crobes that are just nor­mal in­hab­i­tants on us, the ones we evolved with. We’re tak­ing them out of the equa­tion.”

Does that mat­ter? Con­sid­er­ing that the mi­cro­biome not only in- flu­ences how we live but also, in more cases than not, how we age and die, the an­swer is a def­i­nite yes. Mi­cro­biota not only help us di­gest food but they sup­ply nu­tri­ents and pro­tect us against dis­ease-caus­ing pathogens. If the mi­cro­biome is out of whack, which it is more of­ten than not in older and el­derly peo­ple, it may lead to or con­trib­ute to cer­tain dis­eases.

In fact, the mi­cro­biome is im­pli­cated to some ex­tent in many causes of death in older peo­ple. “We know diet can im­prove your health and longevity; we know that ex­er­cise helps,” says Fin­lay. “But the re­ally star­tling thing for me is that mi­crobes are at the in­ter­face of all these things.” One of the top causes of death is in­fluenza and pneu­mo­nia – ob­vi­ously mi­cro­bial as each is caused by a virus or bac­te­ria. But many oth­ers have mi­cro­bial link­ages, rang­ing from de­men­tia and Alzheimer’s all the way to car­dio­vas­cu­lar dis­ease – heart at­tack and strokes – to kid­ney dis­ease and lung dis­ease.

The mil­lion-dol­lar ques­tion is if you en­hance the com­po­si­tion of your mi­crobe pop­u­la­tion, can you in­crease longevity? “I’m con­vinced you can in­crease your healthy liv­ing,” says Fin­lay, “and also your healthy ag­ing.” In one of the largest stud­ies of the hu­man mi­cro­biome, re­searchers in Lon­don, Ont., and China looked at 1,000 “ex­tremely healthy” peo­ple rang­ing in age from three to more than 100 who had no known health is­sues and

no fam­ily his­tory of dis­ease. The re­sults pointed to a di­rect link be­tween a healthy gut and healthy ag­ing. “The main con­clu­sion is that if you are ridicu­lously healthy and 90 years old, your gut mi­cro­biota is not that dif­fer­ent from a healthy 30-year-old in the same pop­u­la­tion,” Greg Gloor, a pro­fes­sor at Western Univer­sity and the prin­ci­pal in­ves­ti­ga­tor, said last fall.

In the hand­ful of ar­eas in the world where peo­ple rou­tinely live long, healthy lives – Ok­i­nawa, Ja­pan; Loma Linda, Calif.; Sar­dinia, Italy; Ni­coya, Costa Rica; Ikaria, Greece – three re­cur­rent themes emerge. The first is the main­tain­ing of so­cial con­tact, whether it’s from gen­er­a­tions liv­ing to­gether or a spir­i­tual com­mu­nity or just reg­u­lar con­tact with friends and fam­ily. It’s not only good for the soul but it’s a good way of mix­ing up the mi­crobes be­cause they’re passed by touch or by touch­ing some­thing some­one else has touched. “You can ac­tu­ally tell who peo­ple are play­ing bridge with in an old folks’ home by their mi­crob- ial sig­na­ture,” says Fin­lay, “be­cause they’re shar­ing these things.”

The se­cond is ex­er­cise – ex­er­cise af­fects mi­crobes and mi­crobes af­fect ex­er­cise. In a cou­ple of re­cent stud­ies out of the Univer­sity of Chicago at Ur­bana-Cham­paign, re­searchers found that ex­er­cise alone changed the com­po­si­tion of the mi­cro­biome in the gut, in­de­pen­dent of any other fac­tors. “You don’t have to be a marathon run­ner,” adds Fin­lay, “but you want to be tod­dling down to the town square to play cards with your bud­dies ev­ery day or be a sheep herder or play ten­nis.”

And, of course, diet is key. Sci­en­tists have found that those who fol­low a mod­i­fied Mediter­ranean diet – high in fruit and veg­eta­bles, nuts and legumes, with fish moder­ately of­ten, red meat only oc­ca­sion­ally – are about 50 per cent less likely to de­velop those more com­mon dis­eases. And it’s never too late to change di­etary habits and have a pos­i­tive im­pact on the mi­cro­biome. (Re­searchers are still try­ing to study the im­pact on the mi­crobi- ome of eat­ing or­ganic ver­sus nonor­ganic, but cur­rently there’s no ev­i­dence show­ing good or bad. But go­ing or­ganic where pos­si­ble cer­tainly can’t hurt.) “If you have a de­fec­tive gene, in to­day’s medicine we can’t fix it, we can’t do gene ther­apy,” says Fin­lay. “Yet it’s easy to change your mi­crobes. We do it ev­ery time we go on a diet, ev­ery time we take an­tibi­otics, ev­ery time we travel to an­other coun­try. So that raises a lot of hope.”

And that’s the best news of all: we aren’t com­pletely pow­er­less to change how we age. In fact, only 20 to 25 per cent of longevity and healthy ag­ing is ge­netic, which means we can con­trol the other 75 per cent. “It’s not writ­ten that you’re go­ing to get cancer and die like your par­ents did,” says Fin­lay. “I think that’s some­thing peo­ple don’t re­ally re­al­ize. We can re­ally in­flu­ence our longevity and health by mod­i­fy­ing the en­vi­ron­ment – ba­si­cally mod­i­fy­ing the mi­crobes be­cause they are how we in­ter­face with the en­vi­ron­ment.”

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