Human Microbiome

00:01 Hello, and welcome to bacteria.

00:04 We're going to dive a little bit deeper into how bacteria cause disease.

00:09 And after you've watched this video, you will understand the extent, origin and functions of the human microbiome.

00:16 You'll appreciate the ways that bacteria enter and spread in their hosts, you'll be familiar with the different types of bacterial toxins and their activities.

00:27 And you will know the mechanisms of action of members of the different classes of anti microbials and how resistance emerges.

00:37 Before we talk about bacteria that cause disease, it's very important to first discuss the human microbiome, all of the microbes that live in and on us, We're home to trillions of microbes, trillions, and that's what we call the microbiome.

00:58 And it's a composition of all the microbes that are everywhere in us and on top of us.

01:03 A human body is only 25% human cells.

01:08 Look, you can see me, you think you're looking at just human cells.

01:14 75% of what you see here are bacteria, very, very little human cells, bacteria, fungi, and archaea.

01:26 It's amazing.

01:29 Wherever the human body is exposed to the outside world, there's a microbial community, the mouth, the lungs, the GI tract, the urogenital tract, the skin, and probably other places, we haven't even found it yet.

01:45 This microbiome is just beginning to be unraveled.

01:49 In terms of what it does for us, it certainly helps us to extract the energy and nutrients from the food we eat.

01:58 But it also appears to inhibit the growth of pathogens not only in us, but on our skin.

02:03 The microbes on our skin produce antimicrobial compounds that protect us.

02:08 It's remarkable.

02:10 There's probably much more that the microbiome does.

02:13 For example, recently, it's been shown in animals, that the microbiome helps their immune system to develop.

02:21 Really, really remarkable.

02:23 In the coming years, we'll be able to sort all of this out but it's quite clear from the very early days of our existence, when we're first born, our microbiome forms, and it has a huge impact on our health.

02:39 Microbes contribute an extra 2 million genes to the 20,000 or so genes that our human genome encodes 99% of our genes are bacterial, isn't it remarkable? Our microbiome weighs two and a half pounds.

02:58 That is weight you'll never be able to get rid of.

03:01 You can try and lose some of your body fat, but that two and a half pounds of microbiome needs to stay with you.

03:06 Otherwise, you're going to be very unhealthy.

03:08 And don't forget the viruses.

03:10 Well, those bacteria and fungi and archaea in us, they also are accompanied by their viruses.

03:17 In fact, viruses outnumber bacteria by about five to one in us.

03:21 And it's quite clear that they have major roles in regulating the microbiome.

03:28 The volume of the microbiome is about three pints.

03:31 The next time you drink three pints of beers, I want you to remember, you've just drunk the volume of your microbiome, by way of getting you to remember what I'm telling you here.

03:43 Now, where do you get this microbiome? There are many ways.

03:48 While you're developing in utero, you are bathed in amniotic fluid provided by your mother.

03:55 And of course, it's going into your mouth and on your skin.

03:58 And it's got bacteria and viruses in it.

04:00 So that's your first encounter.

04:02 You're acquiring your microbiome in utero.

04:06 Then as you're born, you acquire more of your microbiome during birth.

04:12 If you so happen to have been born by passage through the birth canal, you will start to acquire the bacteria that are present along that canal, not just in your mouth but on your skin.

04:24 People who are born by cesarean section, they don't go through the birth canal.

04:29 Of course, they come out through an opening in the skin produced by surgical manipulation.

04:34 They have a very different skin microbiome from children who are born vaginally, so it's probably better to be born through the normal routes.

04:44 You acquire probably a more beneficial microbiome.

04:48 But of course, in some cases, it's not possible for health reasons.

04:52 You also acquire a good amount of your microbiome from your mother.

04:56 Your mother is one of the first to hug and kiss you and she continues to do so hopefully, for the rest of your life, and your father also contributes, and any caregivers who may come into your home.

05:08 They're all contributing to your microbiome.

05:11 Breast milk is a very important contributor to your gut microbiome.

05:16 Again, breastfeeding is not done by everyone.

05:19 But it's been shown in many studies to be better indicators of subsequent health.

05:25 You also acquire microbiome from the soil that you may touch.

05:30 You should let your kids play in the soil, it'sprobably good for them to help acquire their microbiome from the water that you wash yourself in and drink, from the foods that you eat, and any people or pets or plants that you encounter early on in your life, the early years or formative years.

05:46 And then you acquire a relatively stable microbiome that is very similar to that of your family.

05:53 And only when your health changes where if you move or change your diet do you change your microbiome.