that's tricky and. 30 minutes on. they want to know what makes the germans you just. love here and balancing the way for. a live in ottawa my own car and everyone with a lead a holes in every birth getting you ready to meet the germans then join me right just do it under. the human guts it's sad that we know less about it than about the surface of the moon what we do know is that the foods we eat kind of effect our health and that of our immune system for instance too much stuff like this is bad for us. the science is probing our intestines in order to understand more about diet and digestion. we'll be looking at these

topics and more on this edition of tomorrow today. to begin with we go on a fantastic voyage it recalls the 1966 film of the same name in which to me. the shrunken human crew sets off on a perilous mission within the body of a sick man to save him in the nick of time. well tiny nano subs are now real they can navigate the eyeballs of dead pigs and one day they will deliver meds to humans our eyes if all goes according to plan. with modern technology taking a look at the retina on the back wall of an eye is easy and routine but actually going in there to treat disease is much harder i drops aren't enough to tackle serious issues. corkscrew shape now i know robots might be the solution they're

200 times smaller than the diameter of a human hair this is a computer animation. the idea is to send such nano propellers through the vitreous humor of the eye to deliver medicine to the retina professor pear fisher at the max planck institute for intelligent systems in stuttgart is among the scientists who are developing these nano robots. by the invicta in developing the nano propeller we found inspiration in bacteria we recreate the screw like structure that enables bacteria to move because when you rotate a corkscrew it moves forward all that's what makes. the nano propellers are made by they pariahs in silicon dioxide and other materials including iron onto a copper or silicon wafer under high vacuum while it rotates. the way

for is already coated with tiny polymer particles. and each one of his local nano propeller is borne out of the vapor. this way for is covered in billions of these nano propellers. you need a microscope to see them. they are very small and they fit to mash of the vitreous they are only 500 not only there in the average there and to white hall so they can easily sneak through the mesh of the vitreous. the propellers have to be harvested from the way for. bits of the way for are broken off and put into water. and ultrasonic bath disperses the particles. each try. contains a large number of them. for

a nano propeller to move through a body without getting stuck it has to be both tiny and slippery. so the team developed an anti stick coating. the chemical for the coating is called fluorocarbon so it's a long chain carbon that doesn't want to stick to anything so it's a life. similar to the coating of your. for cooking. at tubing in university i hospital nano propellers have been tested in the eyeballs of dead pigs and shown to work. the nano robots are magnetic so they can be steered by electromagnets outside the ai. their movement can be observed in real time with the help of an imaging

technique known as optical coherence tomography. reduce america's best monitor live how the particles move through the eye and we were able to steer them to be exact spot they were meant to go in order to establish that the nano propeller had really reached the retina the pig's eyes were frozen and then cut into thin slices. the microscope revealed that the propellers shown here in red had indeed arrived at the retina near blue ringback. before such nano drug delivery vehicles can be used in clinical practice several problems need to be solved. how can they be removed from the eye again. and how can they. be made to carry and release a cargo of medicine. to load

a nano propeller we can make use of the chemical act or buttes of its surface to attach certain molecules so by means of a chemical process we can also make the helical body porous and they've going molecules to be transported within the mall to create. if and when all the obstacles are overcome this new technology could revolutionize the treatment of diseases of the retina but not only the retina. many parts of the human body are hard to access in a minimally invasive manner. tiny slippery steerable submarines likelihoods might be able to reach parts other methods kept. submarines explore the deepest reaches of the oceans and the bizarre life forms that thrive thing. but there are all mysterious realms to be explored much closer

to home. one prime candidates is our guts our gastrointestinal tract all 9 metres of it it's teeming with wildlife we can't do without. so let's go exploring. introducing luisa. the german name for the common european pair grown by the shores of lake constance . it's about to go on a journey through the human digestive system. and it's a pretty rough ride from the get go our teeth take care of the basic mechanical side of breaking down the fruit next the ground up food costs to be a softer guess on into the stomach. the reason the pair then spends an hour or 2 drenched in the massive pot in preparation for the next stage and that takes place

in the small intestine. for an insider's view scientists at this german medical research center have a cutting edge swallow ball camera at their disposal but for all the gotcha tree precious little is known about the inner workings of our intestines. included. in the foliage the micro biome is largely still an unknown entity within our body even more so than much of the surface of the moon it's something we've only been able to start examining very recently in that respect it's like a black hole shots is. the 1st part of the small intestine has no microorganisms and is remarkably smooth louisa's trekked through this part of our body takes about 3 to 7 hours. the surface area for digestion is greatly increased by countless little projections called villa this is where the body extracts most of the

nutrients which are broken down with the help of enzymes as the parent tells deeper it encounters more and more microorganisms. argos is home to over a 1000 different species of viruses fun guy and bacteria which make up over 90 percent of our intestinal flora as well as helping us on the digestive front they also play a vital role for our immune system they even provide us with nourishment from the products of their metabolism in the form of visions for example. moving around stimulates our digestion what remains of the pair has not reached the large intestine or colon where it will now spend the longest period of its journey between 25 and 30 hours. once in the cold on the ease of the pair is set upon by legions of microorganisms extracting everything the body has not yet been able to digest. their prime target is louisa's dietary fiber on the

polysaccharides it contains. once broken down they used short chain fatty acids beauty rate for example is used by cells in the gut lining as an energy source this is why a healthy diet includes plenty of fiber from vegetables. any major shift in the balance of bacteria can lead to dangerous complications. because i know. we know for sure that when particular bacteria are killed by prescribing antibiotics other bacteria overrun the gut flora. that can lead to a serious inflammation of the colon which is called pseudo membrane miss colitis. so while film good bacteria are more or less wiped out there are harmful bacteria that are resistant to antibiotics and can now multiply on checked such as close

tritium deficiency of. these pathogenic bacteria produce a toxin that attacks the god lining and compromises its ability to protect our body from infections. by the end of its journey the pair has been almost completely decomposed but our body ends up expressing it is largely dead intestinal cells and bacteria practically no residual food. and in the case of louise of the pair it's the fiber that makes the journey so worthwhile for the benefit of our micro biome. several kinds of fruit give us plenty of that good diet because of the pectin found in them. some kinds of pectin might even help cholesterol levels so benign as for example are a great food for many people. here in the us sent in an interesting question about how bananas reproduce. grew from

seeds. wild bananas do have seeds stony blank's needs that can germinate. normally with flowering plants pollen from one flower is carried to an. other where it travels to the ovary and fertilize egg cells to make seeds. the seeds containing the genetic information to produce a new plant the commercial bananas we buy in supermarkets don't contain any seeds they're specially bred to be seedless to make them tastier. these bananas are in fact the result of a genetic accident that gave their cells 3 copies of each chromosome instead of the usual 2. that made them seedless much tastier but also steroids

the most common banana is the cavendish they're all genetically identical each one is a clone of the other. new banana plants are bred from off shoots of a mother plant. 'd worldwide most bananas are bred by taking cuttings and growing new trees. the advantage of this cloning system is that all bananas have the same thick skin the same speed and can be transported at the same time. the disadvantage is that this genetically fragile fruit is vulnerable to diseases the fungal disease tropical race for is currently ravaging the global banana industry from asia to black in america. researchers are currently looking to save the world's most popular fruit from extinction by cross-breeding the cavendish banana and the more robust wild banana.

sweet things have a huge fan base among as you. claim we are programmed to crave them. as a quick source of energy for our body something our stone age ancestors should evaluate . now adays we need as much energy to hunt and forage for ourselves. but that doesn't stop us from craving sweet stuff which comes from a number of sources. cakes and candy that a sweet and shook at us. that's the mission of researches here at brain biotech in

central gemini they're looking for sweetener that's not artificial. and there's one crucial qualification for that natural ingredients. we want to find a sweetener the tastes just like sugar or enhances sugar to a degree where you need less of it but with an identical taste of the old products it's. a requirement that mostly there's today to fail to meet which is why a lot of people aren't keen on them. and research is a still not sure about how exactly artificial sweeteners work in the body 'd aspartame has been comprehensively tested and whitely approved but critics say it's linked to a range of side effects such as headaches and impaired vision. researches have also discovered that unlike sugar sweeteners do not release the time it's the hormones so people who consume them feel less full they also fail to activate the reward

center in the brain the results will be eating more and even gaining more weight despite sweetness having next to no count of rings almost all sweetness approved by the e.u. are artificial the sole exception is stevia approved by the e.u. in 2011. its actual use is however limited. doctored if there are products that don't work very well in conjunction with stevia hardly any dairy products are sweetened with it for example due to the off labors being too pronounced we're looking for a superior sweetener superior version of stevia as opposed to. a super version that also meets taste expectations and that involves breaking down the building blocks of nature these researches have a deep freeze. storage cells and natural substances from countless amounts and

funky and to so far analyzed 20000 samples the vital substances can be hidden away in edible or inedible components in tiny molecular compounds that contain mia traces of that all important sweetness among today's test subjects is red meat one single plant can contain hundreds if not thousands of compounds which will need to be tested in a complex and costly process. but they have helped in the shape of an artificial tongue. the sanctions had this is the most vital element in our research these artificial cells enable us to quickly test the properties of thousands of substances and how sweet or bitter they are each of these tiny vials contains taste cells extracted from the human tongue they react to the samples tested once the cells receive a sweet signal they release messages that in turn become visible the plethora of

light signals show that the red meat has plenty of potential. but it takes a real human being to tell the difference the researches have subjects compared to samples number 2 is the natural variety taken from the brand. to the 1st sample tasted sweeter but it's where the 2nd had a slightly metallic aftertaste. which doesn't bode well for the red meat samples that fail at this stage are of no interest to the reception's. another candidate gets top marks in the taste from a sweet protein from the pen to decline drab their fruit native to central africa but taste is not the only factor for the suitability of substances varies depending on the product. there are sweeteners that are great for drinks because they

dissolve so well whereas some sweeteners have an excellent test but aren't so soluble they're better suited for candy bars or chewing out. of any. kind while taste is important so with the short and long term effects of sweetness . it will take some time until a sweetener is found that is most effective for all products and of course natural. not always bad for us it depends on what kind and how much. polysaccharides found in complex carbohydrates and grains for example don't cause blood glucose levels to spike they're also considered beneficial dietary 5. simple carbs which break down fast into sugar are found in candy they usually don't make you feel full and do make blood glucose levels which is bad contribution to obesity and disease

losing weight can be difficult and hard work can science help us to cut corners. imagine a c from effective pill that will really make your fact go away that's what t.-mo miller and his colleagues are working on and they say they're getting close. to god and it came as a surprise but we were delighted for it. the breakthrough involves using 2 substances one that burns fat and one that suppresses the appetite to create an effective combination therapy. there have been countless attempts to find ways to help people lose weight many pills are touted as the real thing. online you can buy any number of products that claim to do wonders without you having to do more exercise or eat less most of these claims have been shown to be bogus some products

are downright dangerous. the researchers at the home holds diabetes center in munich aim to harness a certain capability of the human body but was only discovered a few years ago brown adipose tissue or brown fat doesn't store energy but uses energy to generate heat quite unlike regular white fat. there are deposits under the collar bone in the neck and along the spine cold temperatures stimulate brown fat we only have a few grams of it but it plays an important role in maintaining body temperature and burning fat the idea was to develop a substance that mimics cold in activating our energy metabolism. when participants in an experiment spend hours in a room left at 16 degrees celsius the volume of that brown fat grows in the same effect to be generated without the chill factor t.-mo miller says the way to do it

is to deploy a substance called isolate. is an agent that activates signaling mechanisms in the brain which in turn activated brown fat fit. the upshot is that the energy metabolism speeds up and bodyweight declines. in tests with mice it works but the amount of weight loss is modest so something else is needed another component to the fat therapy. there are so many non-prescription weight loss pills out there and many are entirely useless some are worse than useless they're harmful even if they claim to be. works at the german institute human nutrition in pottstown. times there are various substances that bind fat in food but the effects are

variable and mostly minimal it seemed almost always come with side effects when large amounts of dietary fat don't get absorbed into the body but remain in the gut it's broken down by bacteria that causes intestinal problems diarrhea or gas it can be very uncomfortable i can't recommend it. so in theory. it gets really dangerous when diet pills include banned substances that are toxic. to trymaine in particular has been associated with serious cardiovascular events that's why it's not licensed for use in the european market but products containing it can still be found and purchased on line d.m.p. is also known to be extremely dangerous it's very toxic one gram can kill you as it burns fat and carbs the metabolism speeds up and the body gets hotter and hotter. at the helm holtz diabetes center they're looking for an agent with negative side

effects. iceland does indeed stimulate the energy metabolism and released in mice but the effect is small so what 2nd substance could compliment or boost the effect and here comes the breakthrough discovery. of the 2nd agent is also a synthetic molecule the m.p.p. . very much like nicotine in that it reduces our food consumption but without the negative effects that nicotine has on our brain. it suppresses appetite but not enough to be effective by itself the trick is combining and d.m.p. piece together the effect. is impressive. if you prescribe the 2 together the combination therapy results in much greater weight loss than the to take it separately. and so. you could say that this is

a case of one plus one equals 3. the results in mice have been excellent but there's still a lot of work to do before we humans can benefit from the breakthrough so for now the prescription in many cases but not all continues to be moved more eat less and eat healthy. the problem is right why auburn but even they. do you have a science question. somebody if we answer it on the show will send you a little something as a thank you you can send your question as a video text over its mail come on just ask. you'll find us on our website d.w. dot com slash science or get in touch via twitter facebook. that's

all for now from tamara today next time we'll be diving deep into other fascinating realms see you then for more scintillating science.

ok i want to race. you know water is never far away. water and well and what the people of all the book made of it that's going to be the common theme for my tour of the city today and it's always have a lot on my list and no tour would be complete without a trip to oak spokes famous marionette theater chickie i'm.

coming up on g.w. . is monitoring some. comments on the. top 10 or. even in coronavirus times is not easy to. reach the artists you know scott. armstrong. i was here when i arrived here i slept with 6 people in a room and similar it was hard i was for. i even got white hairs that.

manning the german language hit me up off the face beats me and could help us to mickey to entrap lives and say you want to know their story license her fighting and reliable information for migrants. we have important numerous ways. smoking is healthy. signs are good for the beamers global warming doesn't exist. drugs are the most. well known yet. you have made in my mind. industry just controlling your thoughts. they are tense only see you science. it's not easy to spot i'm saying one thing and history is saying another of. the great books of the

20th century. present day hoaxes. and who's behind the. just done the behavior is unacceptable it will not be allowed. to structuring ignorance starts made good on t w. this is d.w. news and these are our top stories the race to succeed on the americal as germany's chancellor is heating up as her conservative alliance struggles to agree on a candidate for september's general election the standoff is between various premier mako siddha and the head of medicals seaview.